If the sample mean is equal to the population mean, t =

a. the number of degrees of freedom
b. 0
c. the square root of the n
d. exactly the square root of the degrees of freedom

The correct answer is option b. "0".

Explanation:

In statistics, a t test is used to estimate the difference between the mean of two groups. The t value indicates how different the means are, if the sample mean is equal to the population mean, the t value will be equal to 0. If the t value is positive the sample mean will be higher than the population mean; while a negative t value indicates that the sample is lower than the population mean.

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.