Thread: Finding Mean/Variance from Sum of fi

Wondering if anyone could help with this question, i am lost on how to start.

Attachment 21110

The formula u = x + 20 is used to find the standard deviation of the values of x given in a frequency table. It if found that sigma fi = 40, sigma uifi = 112 and sigma ui squared fi = 10208. Find the mean and variance of the values of x.

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