SOLUTION: Q1 Q2 Q3 Q4 Pre-Cal 77 89 91 99 Rule: Round up the computed mean and round-off the computed variance and standard deviation into 2 decimal places) a. mea

Algebra ->  Probability-and-statistics -> SOLUTION: Q1 Q2 Q3 Q4 Pre-Cal 77 89 91 99 Rule: Round up the computed mean and round-off the computed variance and standard deviation into 2 decimal places) a. mea      Log On


   

Question 1167730: Q1 Q2 Q3 Q4
Pre-Cal 77 89 91 99
Rule: Round up the computed mean and round-off the computed variance and standard deviation into 2 decimal places)
a. mean score = 89.00
b. Σ(x-mean)^2 = 248
c. variance = 82.67
d. standard deviation = 9.09
can you check my answer if it is correct base on the rule? thank you.
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
not sure what the rule is, however:

i get:

mean = sum(x) / 4 = 89
sum of squared deviations from the mean = sum(x-m)^2 = 248

population variance = 248/4 = 62
population standard deviation = sqrt(62) = 7.874007874

sample variance = 248/3 = 82.66666667
sample standard deviation = 9.092121131

what you are showing is the sample variance and sample standard deviation.

if that's what you wanted to show, then you got the right answers.