A study was conducted to investigate the effect of coaching on IQ tests. Nine randomly selected students were tested. At α = .05, test to determine if the coaching increases test scores.
A) Reject the null hypothesis
B) Do not reject the null hypothesis

Question

A study was conducted to investigate the effect of coaching on IQ tests. Nine randomly selected students were tested.  At α = .05, test to determine if the coaching increases test scores.
A) Reject the null hypothesis 
B) Do not reject the null hypothesis

Quizplus · Accepted Answer

T₀ = 8 (n = 9, α = .05) Reject H₀ if T⁺ ≤ T₀. Use T⁺ because we are looking for a shift of D_B to the left of D_A (that is, the test scores are going to improve). T⁺= 6.5 ≤ 8 so we can reject the null hypothesis. We reject H₀ at α = .05.Thus, we conclude that the coaching increases test scores. T⁻ = 38.5 and T⁺ = 6.5 T⁻ is the sum of ranks associated with the negative paired differences. T⁺ is the sum of ranks associated with the positive paired differences. 11ead627_0a08_5ca7_93a1_8b948f5ba73a_TB7056_00

A Study Was Conducted to Investigate the Effect of Coaching