The weight of a small Starbucks coffee is a random variable with a mean of 360 g and a standard

deviation of 9 g. Use Excel to find the weight corresponding to each percentile of weight.
a. 10th percentile b. 32nd percentile c. 75th percentile
d. 90th percentile e. 99.9th percentile f. 99.99th percentile

1 answer

I don't know how you are using Excel, except if it has the proportions of a normal distribution.

Z = (score-mean)/SD = (score-360)/9

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the Z scores that correspond to the above proportions. Insert the Z scores in the equation above to find the scores(weights).