# COMPLETE: Questions #1, #4, #6, #7, #9, #10, #11, and #12 in Chapter 5 of the Ta

COMPLETE: Questions #1, #4, #6, #7, #9, #10, #11, and #12 in Chapter 5 of the Tanner text (pg. 134-136) AND Questions #1, #2, #3, #5, #6, #9, and #10 in Chapter 6 of the Tanner text (pg. 168-169).
Part I
1) If all the teachers and clerical personnel in a school district have an average age of 37.5 years, what will be the value of the mean of the distribution sample means (uM) created from such a population?
4) The clerical staff in the college of sciences have the following job performance scores: 35,37,38,42,47,48,51. Based on the parameters in item 3, and at p= .05, are they significantly different from students in the college as a whole?
6)The admissions officer at a graduate school notes the following scores on the quantitative portion of the Graduate Record Exam (GRE) 425,450,480,510,510,550,560,590,600,625,650. If the national mean is 500 with a standard deviation of 100
a. At p= .05, is this chiroup characteristic of the national population?
b. What’s the probability that a group of applicants to graduate school would score at the level of this sample or higher?
7) Given the mean and standard deviation for GRE scores among the population of students aspiring to graduate school noted in item 6
a. How large must the sample be in order to vary no more than 10 points from the standard deviation of the population with .95 probability?
b. How large must the sample be to be within 5 points of the standard deviation with a probability of .99?
9) A university sponsors a re-entry program for students who have been away from the institution for a year or longer and are re-enrolling. The director of the program knows that the average age of students at the university is 23.830 years, with a standard deviation of 5.0. The ages of a sample of re-entry students are as follows: 19,22,23,25,26,27,27,28,32,37
At p= .05, are their ages significantly different from the ages of students at the university generally?
10) A nationally administered reading test has u= 55.849 and 0 = 8.492
a. How large would a sample need to be in order to be within 2 points of the standard deviation with .95 confidence?
b. at P= .05, are students whose scores are the following characteristic of students nationwide? 38,42,45,46,49,52,55,57
11) On a test of motor dexterity for kindergarten children, the national mean is 14.557, with 0m= 1.754. A group of kindergarten students who manifested fetal alcohol syndrome in infancy have the following scores: 6, 6, 7, 7 8, 10, 10, 11, 12, 12, 14, 14, 16, 18.
A) At p=.05, are their measures of motor dexterity significantly different from the dexterity of children nationality?
B) If the sample represents a population significantly different from the population with u= 14.557, calculate a .95 interval.
12. A sample of college freshman with M=73.428 and 0M = 5.391 are found to have significantly higher scores on the math placement test than is true of all college freshman students.
A. Calculate a .95 confidence interval for the mean of the population represented by this sample
B. How would increasing the sample size impact the breadth of the confidence interval? Why?
Part II
1. A group of eighth grade students in an Honors program have the following reading comprehension scores: 67,55,88,74,69,81,72,70
a. What is the value of SE M?
b. Is the group representative of the population of all eighth grade students for whom iu=66.0?
2) The admissions officer at a university is reviewing admissions scores from a group of applicants. They are 375,400, 425,425,480,500,510,530. Nationally, the mean is 500 points are these applicants’ representative of the national sample?
3) Eighty grade students have the following reading comprehension scores: 52, 58, 64, 67, 67, 69. 70. 71. Are they significantly different from the honors students in item 1?
5) If a significance test is conducted at p k=.05 and one rejects the null hypothesis, what is the probability of a type I error? Of a type II error?
6) The question is whether verbal reinforcement affects response rate. Subjects in Group 1 are verbally reinforced every time they respond to the instructor’s questions. Subjects in group 2 are not. After 2 weeks, the two groups are compared by gauging the number of students who raise their hands when questions are asked. Group 1: 13,15,12,17,14,14. Group 2: 10,12,12,11,13,9.
a. Does Group 1 perform significantly better than group 2?
b. What is the alternate hypothesis for “a”?
c. What does the value of Cohen’s d? What does it mean?
d. How much of response rat can be explained by whether students are reinforced(w2) ?
9. A college counselor wonder whether second semester students take fewer units than first semester students. From the population of each group she selects 10 at random. Before she can secure the data, one of the second semester students transfers to another school leaving her with the following:
First semester students: 10,12,14,14,15,15,15,16,16,18
Second semester students: 6,9,9,10,12,12,12,13,14
a. Is this a one-or two-tailed test?
b. What is the alternative hypothesis in this case?
c. How would you explain the effect size (d)?