Answer:
Explanation:
We want to determine a 95% confidence interval for the population mean for the prices of slice toasters.
Number of sample, n = 12
Mean, u = $61.12
Standard deviation, s = $24.62
For a confidence level of 95%, the corresponding z value is 1.96.
We will apply the formula
Confidence interval
= mean ± z ×standard deviation/√n
It becomes
61.12 ± 1.96 × 24.62/√12
= 61.12 ± 1.96 × 7.107
= 61.12 ± 13.93
The lower end of the confidence interval is 61.12 - 13.93 =47.19
The upper end of the confidence interval is 61.12 + 13.93 = 75.05