Question

A scientist is weighing each of 30 fish. She obtains a mean of 30 g and a standard deviation of 2 g. After completing the weighing, she finds that the scale was misaligned and always under reported every weight by 2 g that is, a fish that really weighed 26 g was reported to weigh 24 g. What is the mean and standard deviation after correcting for the error in the scale

Answer 1

Correct mean = 32 grams

Correct Standard deviation = observed S.D = 2 grams

Explanation:

We are told in the question above :

A scientist is weighing each of 30 fish. She obtains a mean of 30 g and a standard deviation of 2 g. After completing the weighing, she finds that the scale was misaligned and always under reported every weight by 2 g that is

The mean after correcting the error in the scale is :

= observed mean + 2g

= 30g + 2g = 32g

The standard deviation after correcting the error in the scale remains the same as the difference of 2g has no significant effect on the Standard deviation.

This standard deviation = 2g