Answer to Question #137254 in Psychology for saakshi

Question

On a numerical ability test consisting of 10 items, the mean of a group of 50 participants was
7.5 and the SD was 2. For the given data, calculate reliability using method of Rational
Equivalence.
Item Probability of 1 2 3 4 5 6 7 8 9 10
getting the correct answer 0.5, 0.8, 0.4, 0.7, 0.6, 0.7, 0.3, 0.7, 0.5, 0.6

Answer 1

The reliability is given by the number of participants divide by multiplication of the mean, standard deviation, and the number of items:

50/(7.5*2*10)

50/150

Thus, the reliability is 0.3.