Do the sample standard deviations target the value of the population standard deviation? in general, do sample standard deviations make good estimators of population standard deviations? why or why not?

If the mean of the sample standard deviations is equal to the population standard deviation, then the sample standard deviations target the population standard deviation and are called an unbiased estimator.  

If the mean of the sample standard deviations is not equal to the population standard deviation, then the sample standard deviations target the population standard deviation and are called a biased estimator.

A biased estimator regularly underestimates or overestimates the parameter.  

you didn't post any answer choices, so its not 100% clear what your teacher is looking for

however, log(15/7) is equivalent to log(15) - log(7)

i'm using the rule log(x/y) = log(x) - log(y)

no because mercury has a density of 13.6 grams per centimeter squared while gold has 19.32 grams centimeter squared

step-by-step explanation: