In: Statistics and Probability
ABC smoke detector manufacturer claims their smoke detectors can last with average of 105 months and standard deviation is 10 months. A consumer agency wants to test if the smoke detectors cannot last 105 months. A sample of 36 smoke detectors were tested with the mean of 100 months. Use the 5 percent level of significance, can the consumer agency proof the smoke detectors cannot last 105 mouths
Solution :
Givan that
= 105
= 100
= 10
n = 36
This is the two tailed test .
The null and alternative hypothesis is ,
H0 : = 105
Ha : 105
Test statistic = z
= ( - ) / / n
= ( 100 - 105 ) / 10 / 36
= -3
The test statistic = -3
P - value = 2 * P (Z < -3 )
= 2 * 0.0013
= 0.0026
P-value = 0.0026
= 0.05
0.0026 < 0.05
P-value <
Reject the null hypothesis .
There is sufficient evidence to claim
Solution :