Question

Find the standard deviation, s, of sample data summarized in the frequency distribution table below by using the formula below, where x represents the class midpoint, frepresents the class frequency, and n represents the total number of sample values. Also, compare the computed standard deviation to the standard deviation obtained from the original list of data values, 11.1. E (1•x?)]-[2<* - x)] SE 0 n(n-1) Interval Frequency 51-57 30-36 2 37-43 3 44-50 6 58-64 11 65-71 35 72-78 29 1 Standard deviation (Round to one decimal place as needed.) Consider a difference of 20% between two values of a standard deviation to be significant. How does this computed value compare with the given standard deviation, 11.1? O A. The computed value is significantly greater than the given value B. The computed value is significantly less than the given value. O C. The computed value is not significantly different from the given value

Answer 1

midpoint (x frequency () xof x²f Interval 30-36 37-43 33 2 66 3 120 40 47 2178 4800 13254 2916 44-50 6 282 51-57 - 54 58-64 54 61 68 671 65-71 35 2380 40931 161840 16312 5 72-78 75 29 2175 87 E 5748 [: 389044 S r{(f* 1)?] - [3 f x2]? ben- (5748)2 S 87 X 389044 87 X 86 S 107.9022 S = 10.4 The computed value is significantly the given greater than value