Question 356637
 Given the following frequency distribution, find the mean, variance, and standard deviation 
error frequency
46-48 22
49-51 23
52-54 23
55-57 9
58-60 7
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The mark is the representative value of ALL the numbers in the class
Find the "mark" for each of the classes:
mark:::frequency
47:::::22
50:::::23
53:::::23
56:::::9
58:::::7
=================
mean = 51.345...
std = 3.514..
variance = 12.348
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Cheers,
Stan H.