1.Use the confidence level and sample data to find a confidence interval for estimating the population mean, . Round your answer to the same number of decimal places as the sample mean.
Test scores: n = 45, x¯¯¯=25.3
, s = 6.5, 90% confidence
Responses
A.(23.7, 26.9)
B.(21.5, 29.1)
C.(0.1, 12.9)
D.(22.7, 27.9)
2.Use the given degree of confidence and sample data to construct a confidence interval for the population mean, . Assume that the population has a normal distribution.
A sample of 40 batteries found the mean life of a battery is 150 hours with a standard deviation of 8 hours. Find a 95% confidence interval for the mean life of a battery.
Responses
A.(149, 151)
B.(145,155)
C.(148, 152)
D.(147, 153)