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of standardized test scores is less than 310 or greaser than 625 10. (20) The fo

ID: 3070147 • Letter: O

Question

of standardized test scores is less than 310 or greaser than 625 10. (20) The following data represent ex.am scoees in a statistics class taught using eaditional lecture and a classroom. (Round to TWO decimal places as needed) (a) (8) Find sample mean, sample standard deviation (SD) and Five-oumber s summary for two methods, respectively. (Using Calculator) Max (b) (2) Which course has more dispersion in exam scores using the range as the measure of dispersion? (c) (2) Which course has more dispersion in exam scores using the sample standard deviation as the measure of dispersion? (d) (5) Find interquartile range for two methods, respectively. Suppose the student in a traditional class who made the lowest exam score was 43 instead of 60. Is this lowest score 43 an outlier? (e) (3) How does this lowest score 43 affect mean? The median? Explain why

Explanation / Answer

(a) using ms-excel following has been calculated

sample mean(x-)=sum(x)/n

sample standard deviation=sqrt(sum(x-x-)2/(n-1))

median is middle observation of the serires, here 5th and 6th are middle observation, so median will be average of 5th and 6th observation

Quartile is Qi=i*(n+1)/4 observation

Q1=(10+1)/4=2.75th observations

Q3=3*(10+1)/4=8.25th observation

(b) flipped (y) has more disperssion

Range = Max- Min

(c) Traditional has more disperssion using sample standard deviation

(d) inter quartile range=IQR=Q3-Q1

since 43 is less than (Q1-1.5*IQR)=(67.25-1.5*12.25)=48.875, so 43 is an outlier

observation outside the range [ (Q1-1.5*IQR),  (Q3+1.5*IQR)] will be known as outlier

following information has been generated using ms-excel to find the

sample mean sample SD Min Q1 Median Q3 Max Traditional (x) 72.3 8.6287633 60 67.25 70.5 79.5 86 Flipped(y) 76.2 7.3756356 64 72 76 78.5 91