purnachand

In order to compare the means of two populations, independent random samples of 206 observations are selected from each population, with the following results: Sample 1 Sample 2 *1 = 4 x2 = 3 si = 160 s2 = 170 (a) Use a 95 % confidence interval to estimate the difference between the population means (41 - 42). < (41 - 4223 (b) Test the null hypothesis: H. : (u1 - H2) = 0 versus the alternative hypothesis: H : (41 - 42) + 0. Using a = 0.05, give the following: the test statistic z = The final conclusion is A. There is not sufficient evidence to reject the null hypothesis that (H1-H2) = 0. B. We can reject the null hypothesis that (M1 – u2) = 0 and conclude that (ui – u2) 0. (c) Test the null hypothesis: H. :(ui – uz) = 29 versus the alternative hypothesis: H: (41 – u2) 29. Using a = 0.05, give the following: the test statistic z = The final conclusion is A. We can reject the null hypothesis that (H1-H2) = 29 and conclude that (un - M2) #29. B. There is not sufficient evidence to reject the null hypothesis that (H1-H2) = 29.

You read a research report of the differences in weight gain in infants on enriched formula (sample 1) and soy-based formula (sample 2). The findings are reported as: t=6.79; p=.006; Confidence interval of the mean difference: 4.76 to 8.43.

What is the hypothesis decision?

 

Reject the null hypothesis

Accept the null hypothesis

Sample 2 is larger than sample 1: the soy-based formula showed greater weight gain in infants than the enriched formula

Sample 1 is larger than sample 2: the enriched formula showed greater weight gain in infants than the soy-based formula

 

You read a research report of the differences in weight gain in infants on enriched formula (sample 1) and soy-based formula (sample 2). The findings are reported as: t=6.79; p=.006; Confidence interval of the mean difference: 4.76 to 8.43.

What is the conclusion statement?

Accept the null hypothesis

Sample 2 is larger than sample 1: the soy-based formula showed greater weight gain in infants than the enriched formula

Reject the null hypothesis

Sample 1 is larger than sample 2: the enriched formula showed greater weight gain in infants than the soy-based formula

 

You read a research report in which the confidence interval of the mean difference is reported as -1.45 to 3.46. You know from this information that:

There is no statistically significant differences between samples

There is a statistically significant difference between samples; the mean of sample 1 is larger than the mean of sample 2

There is a statistically significant difference between samples; the mean of sample 1 is smaller than the mean of sample 2

Which of the following t-test confidence intervals indicate that there is a statistically significant difference between groups?

 

-15.23 to 23.12

-2.57 to -1.58

-0.05 to 5.47

-12.87 to 0.03

   

Which of the following confidence intervals would be associated with a p-value of 0.34, assuming an alpha of 0.05?

 

-2.54 to 1.38

-35.23 to -23.72

0.19 to 0.89

-15.05 to -5.47