Question

The resting heart rates for 80 women aged 46–55 in a simple random sample are normally distributed, with a mean of 71 beats per minute and a standard deviation of 6 beats per minute. Assuming a 90% confidence level, what is the margin of error for the population mean?

0.66
1.10
1.31
1.73

Answer 1

b. 1.10

Explanation:

right on edge

Answer 2

The margin of error can be calculated using the formula:

1. ME = critical value * standard deviation / sqrt(sample size)
2. ME = critical value * standard error

Since we are given the standard deviation and the sample size, we can use equation 1. The critical value is always fixed and can be determined using a t or z graph. For 90% confidence level, the CV is 1.645.

ME = 1.645(6)/sqrt80 = 1.1