Question

Using a sample of 220 people in a neighborhood within San Antonio, researchers find that 99 people call themselves Republicans. 48% of all San Antonians classifythemselves as Republicans. In this research situation

		Ps is .60 and Pu is .50.
		Pu is .48 and Ps is .45.
		We need to perform a t test.
		Pu is 121 and Ps is 99.

After randomly sampling college students, researchers find 45 seniors have an average of 2.75 partners in the last 5 years. 41 freshmen have an average of 1.66sexual partners over the last 5 years. The t (obtained) for this difference was -2.56 while the t (critical) was ± 2.34. What can be concluded?

		Freshmen are more sexually active.
		Seniors and freshman have significantly different number of sexual partners.
		There is no significant difference between the classes.
		Sexual mores are deteriorating.

1. When finding significance involving 2 sampled proportions, we find the value of the population proportion by estimating

   		the value of the sample means.
   		the value of Z (obtained).
   		the sample standard deviations.
   		the sample proportions.

2. An ANOVA test reveals that the average ages of three different samples are 47.56, 47.57, 47.58. Which assumption below is correct?

   		sample standard deviations approach zero.
   		null hypothesis is incorrect.
   		null hypothesis is correct.
   		research hypothesis is correct.

Answer 1

Using a sample of 220 people in a neighborhood within San Antonio, researchers find that 99 people call themselves Republicans. 48% of all San Antonians classify themselves as Republicans. In this research situation

P for sample = Ps = 99/220 = 0.45

P_u = 48% = 0.48

Pu is .48 and Ps is .45

After randomly sampling college students, researchers find 45 seniors have an average of 2.75 partners in the last 5 years. 41 freshmen have an average of 1.66sexual partners over the last 5 years. The t (obtained) for this difference was -2.56 while the t (critical) was ± 2.34. What can be concluded?

t_cal = -2.56

t_tab = -2.34

Since t_cal = -2.56 < t_tab = -2.34

We reject the null hypothesis'

Seniors and freshman have significantly different number of sexual partners.

When finding significance involving 2 sampled proportions, we find the value of the population proportion by estimating

The best estimate for population proportion is sample proportion.

the sample proportions.

An ANOVA test reveals that the average ages of three different samples are 47.56, 47.57, 47.58. Which assumption below is correct?

as three mean are not equal

null hypothesis is incorrect