Stats-Exam 3 answer key PDF

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Statistics for the Social Sciences...

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Stats-Exam 3 ANSWER KEY

1. If the decision in a hypothesis test said to reject Hoo, then we can always make a conclusion that the sample data supports the claim. False

2. The ANOVA test can be used to compare 5 population means. True

3. The Linear correlation coefficient r is the slope of the line. False

4. Select all that apply. The population proportion p can be: A decimal less than 1 A percent

5. A p-value is used to test the claim that less than 0.25 of adults between the ages of 18 and 44 smoke. Of 1088 randomly chosen adults in this age range it is found that 261 of the 1088 smoke. The p-value for this problem is: 0.2206-calc answer

6. Given a Regression Equation as y= 2.356 - 6.43x. Find the following values for a, b, and the predicted value for x=2. a= 2.356

b= -6.43

y= 2.356-6.43(2) = -10.504

7. Given a p-value =2.567  10-7 and =0.05 Make a decision about Ho

p-value< 0.05

Reject Ho

8. Given this table. Answer the following questions in the box below. x y

3 2

5 3

6 4

8 6

9 5

11 8

a) Find the Linear Correlation Coefficient r. r = 0.958 –Calculator answer

b) Is there a linear correlation between x & y? Explain your answer. Yes, because r is very close to 1.

9. Given below are the BMI statistics for random samples of males and females. Male BMI

n=40

x bar=28.44075

s=7.394076

Female BMI

n= 40

x bar= 26.6005

s=5.359442

note: x bar is the sample mean. Test the claim that males have a higher BMI than females. a) Find Ho and H1 Ho: 1=2 H1: 1 > 2

b) Find the p-value =0.1033-calc answer

Compact Cars

643

655

Midsize Cars

469

427

Full-size Cars

484

456

10. Suppose the National Transportation Safety Board wants to examine the safety of compact cars, midsize cars, and full-size cars. It collects a sample of three for each of the treatments (cars types). Test the claim that the mean pressure applied to the driver's head during a crash is equal for all three types of cars. Use α = 0.05

Show your 6 steps labeled in order.

1. Ho: 1=2=3 H1: at least one of them is different than the others

2. α = 0.05

3. p-value=0.00121

4. 0.00121...