Hey guys, im in psychometrics and my professor is not helpful, in that she never responds to emails or assists us in doing these assignments....
I have 2 sets of data, one is the scores students have gotten on a new reading test and the second is what their actual grades were.
I need to find the predictive validity coefficient of the test.
ill post the data
x y
62 74
73 93
88 68
82 79
85 91
77 72
94 96
65 61
91 92
74 82
85 93
98 95
were x is the test scores and y is the actual grades.
sum of x, squared is 948,676
sum of x squareds is 80,442
sum of y, squared is 992,016
sum of y squareds is 84,254
mean of x is 81.17 mean of y is 83
She gave us this formula however, did not tell us how to use it.
r=n∑xy−(∑x)(∑y)n∑x2−(∑x)2√n∑y2−(∑y)2√
How
Can anyone help me here?
Thanks so much, have a good day!
I have 2 sets of data, one is the scores students have gotten on a new reading test and the second is what their actual grades were.
I need to find the predictive validity coefficient of the test.
ill post the data
x y
62 74
73 93
88 68
82 79
85 91
77 72
94 96
65 61
91 92
74 82
85 93
98 95
were x is the test scores and y is the actual grades.
sum of x, squared is 948,676
sum of x squareds is 80,442
sum of y, squared is 992,016
sum of y squareds is 84,254
mean of x is 81.17 mean of y is 83
She gave us this formula however, did not tell us how to use it.
r=n∑xy−(∑x)(∑y)n∑x2−(∑x)2√n∑y2−(∑y)2√
How
Can anyone help me here?
Thanks so much, have a good day!