Assignment 4 - Hypothesis testing PDF

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Hypothesis testing...

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Name: PSYC301 Lab: k #4

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1. Alexia wants to conduct an experiment to test the effect of fast-food commercials on hunger levels. She doesn’t have a strong sense about what kind of effect the commercials will have, so she decides to use a two-tailed (non-directional) hypothesis. Write the appropriate null and research hypotheses for this study – both hypotheses should include “people who have seen fastfood commercials” and “people who have not seen fast-food commercials”.

2. Alexia measures hunger on a scale of 1 to 10. Hunger levels for the population of people who have not seen fast-food commercials are normally distributed (µ = 5.02, σ = 1.24). Alexia sets her cutoff at α = .05 which corresponds to z = ±1.96 for her non-directional hypothesis. The mean hunger rating for her sample of people who have seen fast-food commercials is 7.25. Do these four things: A. Convert the sample mean to a z-score [z = (x – µ) / σ] B. Determine if the sample score exceeds the cutoff C. Determine whether to reject the null hypothesis D. Interpret these results in one sentence

3. James will be conducting a study on the effect of caffeine on sleep. Past literature (and his own personal experience) tells him that consuming large amounts of caffeine means less sleep, so he decides to use a one-tailed (directional) hypothesis. Write the appropriate null and research hypotheses for this study – both hypotheses should include “people who consume large amounts of caffeine” and “people who do not consume large amounts of caffeine”.

4. For people who do not consume large amounts of caffeine, their sleep follows a normal distribution (µ = 6.51 hours per night, σ = 1.32). James sets his cutoff at α = .05, which corresponds to z = –1.65 for his directional hypothesis. From his sample, people who consume large amounts of caffeine sleep an average of 4.15 hours per night. Do these four things: A. Convert the sample mean to a z-score [z = (x – µ) / σ] B. Determine if the sample score exceeds the cutoff C. Determine whether to reject the null hypothesis D. Interpret these results in one sentence...