Question

16. It is believed that spending money on a professional preparation service for the SAT exams will increase your score. Ten students were chosen randomly, five that had taken a preparation class and five that had not. Does this provide evidence that the preparation courses increase the SAT score? Preparation Class 1130 1470 1230630 1030 No Preparation Class 1040 1240 1270 1020 1350

Answer 1

Ans:

16)

Paired t test:

let d=preparation -no preparation

	preparation class	No preparation	d
1	1130	1040	90
2	1470	1240	230
3	1230	1270	-40
4	630	1020	-390
5	1030	1350	-320
		d-bar	-86
		sd	264.6318

Test statistic:

t=(-86-0)/(264.63/SQRT(5))

t=-0.727

df=5-1=4

p-value=tdist(0.727,4,1)=0.2538

Fail to reject the null hypothesis(as p-value is high)

There is not sufficient evidence to conclude that preparation course increase the SAT score.