8 Jennifer needs to estimate the average age of veterinarian

8) Jennifer needs to estimate the average age of veterinarians in Denver. The standard deviation of ages is 16 years. She wants the standard error of her mean to be 2.1 years. How many veterinarians is she going to need to sample to get at least that kind of accuracy?

Solution

Standard error is defined as - (standard deviation) /(sqrt (n))

Where \'n\' is the sample size.

So, 2.1 = 16 / (sqrt(n))

=> sqrt(n) = 16/ 2.1 = 7.619

So, n = (7.619)² = 58.049

Hence, she should investigate approximately 59 veterinarians.