Question

SHOW ALL STEPS CALCULATED BY HAND NO SPSS OR EXCEL ! THANKS

It is assumed that achievement test scores should be correlated with student's classroom performance. One would expect that students who consistently perform well in the classroom (tests, quizzes, etc.) would also perform well on a standardized achievement test (0 - 100 with 100 indicating high achievement). A teacher decides to examine this hypothesis. At the end of the academic year, she computes a correlation between the students’ achievement test scores (she purposefully did not look at this data until after she submitted students grades) and the overall g.p.a. for each student computed over the entire year. The data for her class are provided belowIt is assumed that achievement test scores should be correlated with student's classroom performance. One would expect that students who consistently perform well in the classroom (tests, quizzes, etc.) would also perform well on a standardized achievement test (0 - 100 with 100 indicating high achievement). A teacher decides to examine this hypothesis. At the end of the academic year, she computes a correlation between the students’ achievement test scores (she purposefully did not look at this data until after she submitted students grades) and the overall g.p.a. for each student computed over the entire year. The data for her class are provided below.

Achievement	G.P.A.
98	3.6
96	2.7
94	3.1
88	4.0
91	3.2
77	3.0
86	3.8
71	2.6
59	3.0
63	2.2
84	1.7
79	3.1
75	2.6
72	2.9
86	2.4
85	3.4
71	2.8
93	3.7
90	3.2
62	1.6

1. Compute the correlation coefficient. (3pts)
2. What does this statistic mean concerning the relationship between achievement test performance and g.p.a.? (3pts)
3. What percent of the variability is accounted for by the relationship between the two variables and what does this statistic mean? (3pts)
   v

   Achievement	G.P.A.
   98	3.6
   96	2.7
   94	3.1
   88	4.0
   91	3.2
   77	3.0
   86	3.8
   71	2.6
   59	3.0
   63	2.2
   84	1.7
   79	3.1
   75	2.6
   72	2.9
   86	2.4
   85	3.4
   71	2.8
   93	3.7
   90	3.2
   62	1.6

4. 1. Compute the correlation coefficient. (3pts)
   2. What does this statistic mean concerning the relationship between achievement test performance and g.p.a.? (3pts)
   3. What percent of the variability is accounted for by the relationship between the two variables and what does this statistic mean? (3pts)
      

Answer 1