Matthew K. answered • 12/01/21
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High School Statistics Teacher
Let x = the number of sales called made. Assuming that sales are independent of each other, "x" is a Binomial random variable with p = 0.20, q = 0.80 and n = 350.
We would then want to compute P(x>70). However, this would be very time-consuming for a Binomial distribution unless you are allowed to use a tool such as an Excel spreadsheet. Are you allowed to use such tools? If not, does your teacher want you to use the Normal Approximation of the Binomial?
Matthew K.
Ok, in that case, make two columns: Title one "x" and fill it in with the numbers from 71 to 350. Then, title the other P(x) with the formula =(0.2^A2)*(0.8^(350-A2))*COMBIN(350,A2) in the first cell below the title. Use the fill handle to fill in the rest of that column. Finally, sum the second column by entering =SUM(B2:B281) below the last entry. You should get the answer 0.4681.
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12/01/21
Anto T.
Yes we can use excel.12/01/21