Answer:
The 95% confidence interval for the average number of years until the first major repair is (3.1, 3.5).
Step-by-step explanation:
The (1 - <em>α</em>)% confidence interval for the average using the finite correction factor is:

The information provided is:

The critical value of <em>z</em> for 95% confidence level is,
<em>z</em> = 1.96
Compute the 95% confidence interval for the average number of years until the first major repair as follows:


Thus, the 95% confidence interval for the average number of years until the first major repair is (3.1, 3.5).
Answer:

Step-by-step explanation:




Answer:
6
Step-by-step explanation:
-28-6b=8
-6b=36
b=6
90% of <span>£41 = 90/100 × 41 = </span><span>£36.9
</span>£41 decreased by 90% = 41 - 36.9 = <span>£4.1</span>