Question

You measure 26 turtles' weights, and find they have a mean weight of 39 ounces. Assume the population standard deviation is 12.8 ounces. Based on this, construct a 90% confidence interval for the true population mean turtle weight.

Give your answers as decimals, to two places

±±  ounces

Answer 1

Solution :

Given that,

Z/2 = Z0.05 = 1.645

Margin of error = E = Z/2 * ( /n)

= 1.645 * ( 12.8 /  26 )

= 4.13

At 90% confidence interval estimate of the population mean is,

  ± E

= 39   ± 4.13

= ( 34.87, 43.13 )