Some students that attend college students work full or part time. How much did your working college friends each earn last month? Listed below is the amount earned last month by each student in a sample of 35 college students.
|
0
|
0
|
105
|
0
|
313
|
453
|
769
|
|
415
|
244
|
0
|
333
|
0
|
0
|
362
|
|
276
|
158
|
409
|
0
|
0
|
534
|
449
|
|
281
|
37
|
338
|
240
|
0
|
0
|
0
|
|
142
|
0
|
519
|
356
|
280
|
161
|
0
|
a.) Describe the population of interest.
b.) How many of the students in the sample worked last month?
c.) Describe the variable, amount earned by a working college student last month, using one graph, one measure of central tendency, and one measure of dispersion.
d.) Find evidence to show that the assumptions used for the Student%u2019s t-distribution have been satisfied.
e.) Estimate the mean amount earned by a college student per month using a point estimate and a 95% confidence interval.
f.) Based on records from the US Department of Education it is estimated that college students earn an average of $350. Does the sample show sufficient reason to reject the claim? Use %u03B1 = 0.05
2. A researcher collects data on two independent samples. The first group consists of 20 human subjects, has a sample mean of 4.21, and a standard deviation of 1.4. The second group consists of 20 subjects, has a sample mean of 3.15, and a standard deviation of 1.8. Test the null hypothesis that there is no difference between the population means of the two groups at the .01 level of significance. Indicate a) the observed value of the test statistic, b) the critical value(s), c) whether you reject or fail to reject the null hypothesis.
3. A researcher collects data on two independent samples. The first group consists of 20 human subjects, has a sample mean of 4, and a variance of 5. The second group consists of 10 subjects, has a sample mean of 6, and a variance of 9. Test the null hypothesis that there is no difference between the population means of the two groups at the .10 level of significance. Indicate a) the observed value of the test statistic, b) the critical value(s), c) whether you reject or fail to reject the null hypothesis.