Discover answers to your questions with Westonci.ca, the leading Q&A platform that connects you with knowledgeable experts. Ask your questions and receive precise answers from experienced professionals across different disciplines. Experience the ease of finding precise answers to your questions from a knowledgeable community of experts.

The life in hours of a biomedical device under development in the laboratory is known to be approximately normally distributed. A random sample of 15 devices is selected and found to have an average life of 5625.1 hours and a sample standard deviation of 226.1 hours.

Required:
a. Construct and interpret a 95% (two sided) confidence interval for the population standard deviation of the life of a biomedical device.
b. Test the hypothesis that the true mean life of a biomedical device is greater than 5500 using the P-value approach.


Sagot :

Answer:

Part a [5522.3511 ; 5727.8488]

Part b. The p-value is 0.050115.

The H0 is rejected and concluded that the true mean life of a biomedical device is greater than 5500.

Step-by-step explanation:

The 95 % confidence interval for the mean of the population is given by

∝= 1- 0.95= 0.05

υ= n-1= 15-1= 14

x`± t ∝() s / √n

5625.1 ± { t (0.05) (14)} 226.1 / √15

5625.1 ± 1.76 * 226.1/3.8729

5625.1 ± 102.7488

[5522.3511 ; 5727.8488]

Part b

State the null and the alternate hypothesis

H0: u= 5500  against the claim Ha: u > 5500

the test statistic

t= x`- u/ s/ √n

t= 5625.1-5500/226.1 / √15

t=2.143

The p-value is 0.050115.

The result is not significant at p < 0.05.

The H0 is rejected and concluded that the true mean life of a biomedical device is greater than 5500.