BUS105 PCQ PDF

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Pre course quiz answers for BUS105...

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The ans highlighted in yellow are confirmed and those in light blue are TBC, those who can confirm the ans pls do help to fill in. Thank you! ^-^ Pcq 1 (/100)

A firm offers routine physical examinations as part of a health service program for its employees. The exams showed that 8% of the employees needed corrective shoes, 15% needed major dental work, and 3% needed both corrective shoes and major dental work. What is the probability that an employee selected at random will need either corrective shoes or major dental works? ● 0.25. ● 0.20. ● 1.00. ● 0.50. A board of directors consists of eight men and four women. A four-member search committee is randomly chosen to recommend a new company president. What is the probability that all four members of the search committee will be women? ● 1/8 or 0.125. ● 1/495 or 0.002. ● 1/16 or 0.0625. ● 1/120 or 0.00083. The ABCD football association is considering a Super Ten Football Conference. The top 10 football teams in the country, based on past records, would be members of the Super Ten Conference. Each team would play every other team in the conference during the season and the team winning the most games would be declared the national champion. How many games would the conference commissioner have to schedule each year? (Remember, Oklahoma versus Michigan is the same as Michigan versus Oklahoma.) ● 50. ● 45. ● 125. ● 14. When an experiment is conducted "without replacement," __________. ● The experiment can be illustrated with a Venn diagram. ● Events are equally likely. ● The probability of two or more events is computed as a joint probability. ● Events are dependent. Each salesperson in a large department store chain is rated on their sales ability and their potential for advancement. The data for the 500 sampled salespeople are summarized in the following table.

What is the probability that a salesperson selected at random will have an excellent potential for advancement given they also have above average sales ability? ● 0.404. ● 0.60. ● 0.27. ● 0.45. Sweetwater & Associates write weekend trip insurance at a very nominal charge. Records show that the probability that a motorist will have an accident during the weekend and file a claim is 0.0005. Suppose they wrote 400 policies for the coming weekend, what is the probability that exactly two claims will be filed? ● 0.8187. ● 0.2500. ● 0.0001. ● 0.0164. Which one of the following is NOT a condition of the binomial distribution? ● Only two outcomes. ● The probability of success remains constant from trial to trial. ● Sampling at least 10 trials. ● Independent trials. Sponsors of a local charity decided to attract wealthy patrons to its $500-a-plate dinner by allowing each patron to buy a set of 20 tickets for the gaming tables. The chance of winning a prize for each of the 20 plays is 50-50. If you bought 20 tickets, what is the chance of winning 15 or more prizes? ● 0.006. ● 0.250. ● 0.021. ● 0.750. A farmer who grows genetically engineered corn is experiencing trouble with corn borers. A random check of 5,000 ears revealed the following: Many of the ears contained no borers. Some ears had one borer; A few had two borers, and so on. The distribution of the number of borers per ear approximated the Poisson distribution. The farmer counted 3,500 borers in the 5,000 ears. What is the probability that an ear of corn selected at random will contain no borers? ● 0.4966. ● 1.000. ● 0.0631. ● 0.3476.

A statistics professor receives an average of five e-mail messages per day from students. Assume the number of messages approximates a Poisson distribution. What is the probability that on a randomly selected day she will have no messages? ● Impossible to have no messages. ● 0.0335. ● Zero. ● 0.0067.

Pcq 2 100/100 (done!) The mean amount spent by a family of four on food is $500 per month with a standard deviation of $75. Assuming that the food costs are normally distributed, what is the probability that a family spends less than $410 per month? 0.1151. 0.8750. 0.2158. 0.0362. Question 2 10 pts A study of a company's practice regarding the payment of invoices revealed that an invoice was paid an average of 20 days after it was received. The standard deviation equalled five days. Assuming that the distribution is normal, what percent of the invoices were paid within 15 days of receipt? 86.74%. 34.13%. 37.91%. 15.87%. Question 3 10 pts Which of the following is true in a normal distribution? The mean divides the distribution into two equal areas. The mode and the third quartile are equal. The area under the curve is 0.68. The mean equals zero. Question 4 10 pts What is an important similarity between the uniform and normal probability distributions? The mean, median, and mode are all equal. The mean and median are equal. They are negatively skewed. About 68% of all observations are within one standard deviation of the mean. Question 5 10 pts

According to the central limit theorem, _______________. Increasing sample size decreases the dispersion of the sampling distribution. Sample size is important when the population is not normally distributed. The sampling distribution of the sample means is uniform. The sampling distribution of the sample means will be skewed. Question 6 10 pts Suppose a research firm conducted a survey to determine the mean amount steady smokers spend on cigarettes during a week. A sample of 100 steady smokers revealed that the sample mean is $20 and the sample standard deviation is $5. What is the probability that a sample of 100 steady smokers spend between $19 and $21? 0.0228. 0.9544. 0.4772. 1.0000. Question 7 10 pts A statewide sample survey is to be made. First, the state is subdivided into counties. Seven counties are selected at random and further sampling is concentrated on these seven counties. What type of sampling is this? Stratified sampling. Simple Random Systematic random sampling. Cluster sampling. Flag this Question Question 8 10 pts Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones Brothers has maintained careful records regarding the time to prepare a return. The mean time to prepare a return is 90 minutes and the standard deviation of this distribution is 14 minutes. Suppose 100 returns from this year are selected and analysed regarding the preparation time. What assumptions do you need to make about the shape of the population distribution of all possible tax preparation times to make inferences about the mean time to complete a tax form? The population distribution is skewed to the right. The population distribution is skewed to the left. The population distribution is normal. The shape of the population distribution does not matter. Question 9 10 pts An experiment involves selecting a random sample of 256 middle managers for study.

One item of interest is their annual income. The sample mean is computed to be $35,420, and the sample standard deviation is $2,050. What is the sample standard error of the mean? $128.125. $8.01. $2,050. $138.36. Question 10 10 pts The Office of Student Services at a large western state university maintains information on the study habits of its full-time students. Their studies indicate that the mean amount of time undergraduate students study per week is 20 hours. The hours studied follows the normal distribution with a standard deviation of six hours. Suppose we select a random sample of 144 current students. What is the probability that the mean of this sample is between 19 hours and 20 hours? Cannot be calculated based on the given information. -2.00. 2.00. 0.4772. Pcq 3 (100/100) Question 1 10 pts The mean number of travel days per year for salespeople employed by three hardware distributors needs to be estimated with a 0.90 degree of confidence. For a small pilot study, the mean was 150 days and the standard deviation was 14 days. If the population mean is estimated within two days, how many salespeople should be sampled? 452. 133. 2,100. 511. Question 2 10 pts Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The results showed that the mean tread life was 50,000 miles, with a standard deviation of 3,500 miles. What is the best estimate of the mean tread life in miles for the entire population of these tires? 50,000. 3,500. 35.

500. Question 3 10 pts How is the t distribution similar to the standard z distribution? Both are discrete distributions. Both are skewed distributions. Both are families of distributions. Both are continuous distributions. Question 4 10 pts When a confidence interval for a population mean is constructed from sample data, __________. We can conclude, for an infinite number of samples and corresponding confidence intervals that the population mean is in a stated percentage of the intervals. We can conclude that the population mean is in the interval. We cannot make any inferences. We can conclude that the population mean is not in the interval. Question 5 10 pts A random sample of 42 college graduates revealed that they worked an average of 5.5 years on the job before being promoted. The sample standard deviation was 1.1 years. Using the 0.99 degree of confidence, what is the confidence interval for the population mean? 2.67 and 8.33. 5.04 and 5.96. 4.40 and 6.60.

Question 6 10 pts A university surveyed recent graduates of the English Department for their starting salaries. Four hundred graduates returned the survey. The average salary was $25,000. The population standard deviation was $2,500. What is the 95% confidence interval for the mean salary of all graduates from the English Department? [$22,500, $27,500]. [$24,600, $25,600]. [$24,988, $25,012]. [$24,755, $25,245]. Question 7 10 pts

To test the hypothesis that 55% of those families who plan to purchase a vacation residence in Florida want a condominium, the null hypothesis is π = 0.55 and the alternate is π ≠ .55. A random sample of 400 families who planned to buy a vacation residence revealed that 228 families want a condominium. What decision should be made regarding the null hypothesis using the 0.01 level of significance? Purchase a condominium. Reject it. Cannot accept it or reject it based on the information given. Do not reject it. Question 8 10 pts A consumer products company wants to increase the absorption capacity of a sponge. Based on past data, the average sponge could absorb 3.5 ounces. After the redesign, the absorption amounts of a sample of sponges were (in ounces): 4.1, 3.7, 3.3, 3.5, 3.8, 3.9, 3.6, 3.8, 4.0, and 3.9. At the 0.01 level of significance, what is the decision rule to test if the new design increased the absorption of the sponge? Reject null hypothesis if computed t is less than 2.580. Reject null hypothesis if computed t is less than 2.764. Reject null hypothesis if computed t is greater than 2.821. Reject null hypothesis if computed z is 1.96 or larger. Question 9 10 pts For a two-tailed test with a 0.05 significance level, where is the rejection region when n is large and the population standard deviation is known? Between ±1.645. Between ±1.960. Greater than +1.645 and less than -1.645. Greater than +1.960 and less than -1.960. Question 10 10 pts In a market test of a new chocolate raspberry coffee, a poll of 400 people from Dobbs Ferry showed 250 preferred the new coffee. In Irvington, 170 out of 350 people preferred the new coffee. To test the hypothesis that there is no difference in preferences between the two villages, what is the null hypothesis? H0: π1 < π2. H0: π1 = π2. H0: π1 > π2. H0: π1 ≠ π2.

PCQ 4 100/100

PCQ 5 100/100 only Question 110 pts The main purpose of descriptive statistics is to: Summarize data in a useful and informative manner. Make inferences about a population. Gather or collect data. Determine if the data adequately represents the population. Question 210 pts The performance of personal and business investments is measured as a percentage, "return on investment." What type of variable is "return on investment"?

Discrete. Continuous. Qualitative. Attribute. cigarette Question 310 pts A student was interested in the smoking habits of college students and collected data from an unbiased random sample of students. The data is summarized in the following table:

Why is the table NOT a frequency distribution? The number of males does not equal the sum of males that smoke and do not smoke. The classes are not mutually exclusive. There are too many classes. Class limits cannot be computed. Question 410 pts A group of 100 students were surveyed about their interest in a new Economics major. Interest was measured in terms of high, medium, or low. In the study, 30 students responded high interest, 50 students responded medium interest, and 20 students responded low interest. What is the best way to illustrate the relative frequency of student interest? Use a pie chart. Use a frequency table. Use a box plot. Use a cumulative frequency polygon. Question 510 pts

For the following distribution of heights, what are the limits for the class with the greatest frequency? 64 and up to 70. 65 and up to 70. 65 and 69. 69.5 and 74.5. Question 610 pts Refer to the following wage breakdown for a garment factory.

What is the class midpoint for the class with the greatest frequency? $5.50. $8.50. $11.50. $14.50.

Question 710 pts For any data set, which measures of central location have only one value? Mode and standard deviation. Mean and median. Mode and median. Mode and mean.

Question 810 pts On a finance exam, 15 accounting majors had an average grade of 90. On the same

exam, 7 marketing majors averaged 85, and 10 finance majors averaged 93. What is the weighted mean for all 32 students taking the exam? 10.67. 89.33. 89.84. 89.48. Flag this Question Question 910 pts A bottling company offers three kinds of delivery service: instant, same day, and within five days. The profit per delivery varies according to the kind of delivery. The profit for an instant delivery is less than the other kinds because the driver has to go directly to a grocery store with a small load and return to the bottling plant. To find out what effect each type of delivery has on the profit picture, the company summarized the data in the following table based on deliveries for the previous quarter.

What is the weighted mean profit per delivery? $142. $110. $72. $97. Question 1010 pts The monthly amounts spent for food by families of four receiving food stamps approximates a symmetrical, normal distribution. The sample mean is $150 and the standard deviation is $20. Using the Empirical Rule, about 95% of the monthly food expenditures are between what two amounts? $110 and $190. $100 and $200.

$205 and $220. $85 and $105.

PCQ6 In regression analysis, what is the predictor variable called? ● Dependent variable. ● Correlation variable. ● Independent variable. ● Variable of determination. Which of the following statements regarding the coefficient of correlation is true? ● It is calculated as the square of the slope. ● It describes the relationship between two variables. ● It ranges from 0.0 to +1.0 inclusive. ● A value of 0.00 indicates two variables are related. What is the null hypothesis to test the significance of the slope in a regression equation? ● H0: β ≤ 0. ● H0: β = 0. ● H0: β ≥ 0. ● H0: β ≠ 0 The regression equation is Ŷ = 30 + 2.56X, the sample size is 14, and the standard error of the slope is 0.97. What is the test-statistic to test the significance of the slope? ● t = +2.639. ● z = -2.560. ● t = +2.560. ● z = +2.639. A sales manager for an advertising agency believes that there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned. A regression analysis shows the following results:

What is the decision regarding the hypothesis that the slope equals zero? ● Reject the null hypothesis. ● Reject the alternative hypothesis. ● Fail to reject the null hypothesis. ● Fail to reject the alternative hypothesis. To evaluate the assumption of linearity, a multiple regression analysis should include ___________.

● ● ● ●

A calculation of variance inflation factors. Scatter diagrams of the dependent variable plotted as a function of each independent variable. Hypothesis tests of individual regression coefficients. An ANOVA table.

If the correlation between the two independent variables of a regression analysis is 0.11, and each independent variable is highly correlated to the dependent variable, what does this indicate? ● Only one of the two independent variables will explain a high percent of the variation. ● An effective regression equation. ● A negative relationship is not possible. ● Multicollinearity between these two independent variables. In an ANOVA table for a multiple regression analysis, the regression mean square is __________. ● n - (k + 1). ● The regression sum of squares divided by the regression degrees of freedom. ● The treatment sum of squares divided by the regression degrees of freedom. ● The total sum of squares divided by the regression degrees of freedom. A manager at a local bank analyzed the relationship between monthly salary and three independent variables: length of service (measured in months), gender (0 = female, 1 = male), and job type (0 = clerical, 1 = technical). The following ANOVA summarizes the regression results:

Based on the ANOVA and a 0.05 significance level, the global null hypothesis test of the multiple regression model ___________. ● Will be rejected and conclude that monthly salary is related to at least one of the independent variables. ● Will be rejected and conclude that monthly salary is related to all of the independent variables. ● Will not be rejected. ● Will show a high multiple coefficient of determination. Twenty-one executives in a large corporation were randomly selected to study the effect of several factors on annual salary (expressed in $000s). The factors selected were age, seniority, years of college, number of company divisions they had been exposed, to and the level of their responsibility. The results of the regression analysis follow:

Which one of the following is the dependent variable? ● Age. ● Annual salary. ● Seniority. ● Level of responsibility....