# Question

A school psychologist wishes to determine whether a new antismoking film actually reduces the daily consumption of cigarettes by teenage smokers. The mean daily cigarette consumption is calculated for each of eight teen-age smokers during the month before and the month after the film presentation, with the following results:

When deciding on the form of the alternative hypothesis, H1, remember that a positive difference score (D = X1 – X2) reflects a decline in cigarette consumption.)

(a) Using t, test the null hypothesis at the .05 level of significance.

(b) Specify the p - value for this test result.

(c) If appropriate (because the null hypothesis was rejected), construct a 95 percent confidence interval for the true population mean for all difference scores, and use Cohen’s d to obtain a standardized estimate of the effect size. Interpret these results.

(d) What might be done to improve the design of this experiment?

When deciding on the form of the alternative hypothesis, H1, remember that a positive difference score (D = X1 – X2) reflects a decline in cigarette consumption.)

(a) Using t, test the null hypothesis at the .05 level of significance.

(b) Specify the p - value for this test result.

(c) If appropriate (because the null hypothesis was rejected), construct a 95 percent confidence interval for the true population mean for all difference scores, and use Cohen’s d to obtain a standardized estimate of the effect size. Interpret these results.

(d) What might be done to improve the design of this experiment?

## Answer to relevant Questions

The number of friends reported by Facebook users is summarized in the following frequency distribution: FRIENDS f 400 – above ...... 2 350 – 399...... 5 300 – 349....... 12 250 – 299....... 17 200 – 249....... ...A manufacturer of a gas additive claims that it improves gas mileage. A random sample of 30 drivers tests this claim by determining their gas mileage for a full tank of gas that contains the additive (X1) and for a full tank ...Recall the experiment described in Review Question 16.11 on page 314, where errors on a driving simulator were obtained for subjects whose orange juice had been laced with controlled amounts of vodka. Now assume that ...In Chapter 1, Table 1.1 lists the weights of 53 male statistics students. Although students were asked to report their weights to the nearest pound, inspection of Table 1.1 reveals that a disproportionately large number (27) ...A social psychologist wishes to test the assertion that our attitude toward other people tends to reflect our perception of their attitude toward us. A randomly selected member of each of 12 couples who live together is told ...Post your question

0