Question

Collage students regularly frequent coffee shops as a social venue or convenient study spot for easy access to wifi and caffeine. Suppose hat the cost for a 12-oz cup of the standard house brew of coffee at such establishment gas a mean price of $2.89 with a standard deviation of $ 0.38.

a. What is the z-score for a cup of coffee that costs $2.25?

b. What is the z-score for a cup of coffee that costs $4.25?

c. Interpret the z-scores in parts a and b. Comment on weather either should be considered an outlier.

d. If the cost for a drink with 4 shots of expresso, a shot of vanilla syrup, vanilla spice syrup. protein powder, a Banana. Carmel drizzle , chocolate flakes and cherry is $6.50 is this an outlier?

Explain .

Answer 1

a. Z score is calculated as

X = Variable coffee prices.

u= Mean

Sigma= Standard deviation

b.Z score at X=4.25

c. Since the Z scores is value which calculated the no of standard deviation it is away from the central tendency. In part Z value is -1.684 and in b Z=3.589 whuch outside the normal range of a normal distribution hence 4.25 is an outlier.

d.If there is actually total shots of variety of drinks are :12

Now Z value at 6.50 as

Hence it is an outlier because it lies at Z score way beyond .