Question

In Biology class you learn that the salinity of brackish water (water that is saltier than fresh water, but less salty than ocean water) generally has a mean of 20 parts per thousand (ppt). You go to a nature preserve located near the ocean every day at 4:00 p.m. for 35 successive days and measure the salinity of the water in the estuary (place where fresh water and ocean water mix and mingle) at the same location.   At the end of the time period, you calculate the mean and standard deviation of the salinity of your 35 data points and carry out a one-sample t-test about the mean, calculating the test statistic and the P-value.

What assumption concerning hypothesis testing have you violated in carrying out this experiment?

P-value

Sample Size

Randomness

Unknown population standard deviation

Normality

Answer 1

This study violates randomness assumption as the samples are being take at the same place and at the same time.

Option C is correct.