Statistics Please check (a) (c) (d) to see if they are correct.?

What is the age distribution of promotion-sensitive shoppers? A supermarket super shopper is defined as a shopper for whom at least 70% of the items purchased were on sale or purchased with a coupon. The following table is based on information taken from Trends in the United States (Food Marketing Institute, Washington, D.C.).





Age range, years 18-28 29-39 40-50 51-61 62+


Midpoint x 23 34 45 56 67


% of shoppers 7% 44% 24% 14% 11%





(a) Using the age midpoints x and the percentages of super shoppers, do we have a valid probability distribution? Explain.


Yes, events are distinct and probabilities total to 1.





(c) Compute the expected age µ of a super shopper.


Age P(x) x(P)x


23 0.07 1.61


34 0.44 14.96


45 0.24 10.8


56 0.14 7.84


67 0.11 7.37


µ = ∑xP(x) = 42.58





(d) Compute the standard deviation õ for ages of super shoppers.


√∑(x-µ)²P(x) = √151.442 = 12.31

Statistics Please check (a) (c) (d) to see if they are correct.?
You are correct.





I have verified the calculations





d%26lt;-c(1.61,14.96,10.8,7.84,7.37)





m%26lt;-sum(d)





s%26lt;-c((23-m)^2 * 0.07,(34-m)^2 * 0.44,(45-m)^2 * 0.24,(56-m)^2 * 0.14,(67-m)^2 * 0.11)





sqrt(sum(s))








output:





mean = 151.4436


std dev = 12.30624
Reply:oh my...i dont think anyone is gonna help you with this one....looks like way too much work...10 points isnt worth it

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