How de you find standard deviation

Work out the Mean (the simple average of the numbers)

Then for each number: subtract the Mean and square the result.

Then work out the mean of those squared differences.

Take the square root of that and we are done!

168

step-by-step explanation:

first off, we know that he drove 3.5 hours at a rate of 48 mph.

knowing that, we want to see how many miles he drove all-together.

in this case, we can just multiply 48 by 3.5.

48 * 3.5 = 168

b

step-by-step explanation:

i dont know