Question #137254

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

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

Expert's answer

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.

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