Question

A social psychologist studying mass communication randomly assigned 87 volunteers to one of two experimental groups. Fifty-seven were instructed to get their news for a month only from television, and 30 were instructed to get their news for a month only from the Internet. After the month was up, all participants were tested on their knowledge of several political issues. The researcher simply predicted that there is some kind of difference. These were the results of the study. TV group: M = 23, S2 = 6; Internet group: M = 25, $* = 4. Using the 0.01 level, what should the social psychologist conclude? Complete parts (a) through (e) below. Click the icon to view the table of cutoff scores fort, (a) Use the steps of hypothesis testing. Restate the question as a research hypothesis and a null hypothesis about the populations. There are two populations of interest as shown below. Population 1: People who get their news from TV. Population 2: People who get their news from the Internet. The research hypothesis is that the population mean for the TV group is the population mean for the Internet group. The null hypothesis is that the population mean for the TV group is the population mean for the Internet group. Determine the cutoff score(s) on the comparison distribution for the best (Use a comma to separate answers as needed. Round to three decimal places as needed.) Find the score (Round to two decimal places as needed) Decide whether to reject the null hypothesis. Choose the correct answer below. A Relect the nullpothesis. The difference is statistically sionificant at the 0.01 level Click to select your answer(s) 2

Answer 1

(a) different from, the same as

cutoff score = -2.635, 2.635

t = -3.845

Option A

(b) Graph C

(c) greater, a difference

1	2
23	25	mean
2.449489743	2	std. dev.
57	30	n
	85	df
	-2.000	difference (1 - 2)
	5.318	pooled variance
	2.306	pooled std. dev.
	0.520	standard error of difference
	0	hypothesized difference
	-3.845	t
	.0002	p-value (two-tailed)