In: Statistics and Probability
Carry out (show all steps) the test to answer each of these questions. You may use either the classical method or the P -value method, but you must state the P -value for each problem.
3. A random sample of 15 households in a small city gives the following number of hours of television watched in one week. A marketing firm wishes to determine whether the mean amount of television watching per week is more than 8 hours at the α = 0.10 level of significance.
# hours of television watched 7.5, 6.3, 7.2, 5.0, 7.9,10.7, 8.9, 8.8, 10.3, 8.8, 9.5, 9.5, 6.1, 9.4, 8.4
Solution:
x | x2 |
7.5 | 56.25 |
6.3 | 39.69 |
7.2 | 51.84 |
5 | 25 |
7.9 | 62.41 |
10.7 | 114.49 |
8.9 | 79.21 |
8.8 | 77.44 |
10.3 | 106.09 |
8.8 | 77.44 |
9.5 | 90.25 |
9.5 | 90.25 |
6.1 | 37.21 |
9.4 | 88.36 |
8.4 | 70.56 |
∑x=124.3 | ∑x2=1066.49 |
Mean ˉx=∑xn
=7.5+6.3+7.2+5+7.9+10.7+8.9+8.8+10.3+8.8+9.5+9.5+6.1+9.4+8.4/15
=124.315
=8.2867
Mean = 8.29
Sample Standard deviation S=√∑x2-(∑x)2nn-1
=√1066.49-(124.3)21514
=√1066.49-1030.0327/14
=√36.4573/14
=√2.6041
=1.6137
Sample Standard deviation =1.61
This is the two tailed test .
The null and alternative hypothesis is ,
H0 : = 8
Ha : > 8
Test statistic = t
= ( - ) / S / n
= (8.29-8) / 1.61 / 15
= 0.698
Test statistic = t = 0.698
P-value =0.2484
= 0.10
P-value >
0.2484 > 0.10
Fail to reject the null hypothesis .
There is not sufficient evidence to claim that the population mean μ is greater than 8, at the 0.05 significance level.