how do you find how many standard deviations are within a mean?

Question

jim_thompson5910 · Answer

is that all the question asks?

anonymous · Answer

the exact question is within how many standard deviations of the mean is the cost of $50. The standard deviation is 21.5

jim_thompson5910 · Answer

what value do they give for the mean?

anonymous · Answer

91

jim_thompson5910 · Answer

first we subtract the mean 91 from the cost of 50

50 - 91 = -41

this negative number tells us we are below the mean

jim_thompson5910 · Answer

then we divide the difference by the std deviation

-41/21.5 = -1.9069767

which is approximate

jim_thompson5910 · Answer

so you are roughly 1.9069767 standard deviations below the mean

jim_thompson5910 · Answer

this is using the formula

z = (x - mu)/sigma


x = raw score
mu = mean
sigma = standard deviation
z = z-score

anonymous · Answer

Ok thank you that helped a lot.

jim_thompson5910 · Answer

you're welcome