I have posted the first two questions as well to see if that is somehow impacting my answer?

1. Compute the sample mean x and the sample standard deviation sx of Albertson’s grocery prices.

a. x=3.862

b. Sx = 1.1599

2. State the population mean µx and population standard deviation σx of sample mean x in terms of population mean µx and population standard deviation σx for the original variable x. (Hint: You don’t need to compute anything here. Think back to chapter 6)

a. µx = 3.862

b. σx = 1.1599

3. Find the probability that sampling error made in estimating the mean Albertson’s grocery prices is $ 0.50 or less. (For this problem, assume that the standard deviation σx is known to be $ 1.10).

a.

P(Sampling Error <.50)

Z=(x-µ )÷ ( σ÷√(n)

Z = (4.362 – 3.862) ÷ (1.1599 ÷ √25)

Z = .50 ÷ .23198

Z = 2.155358

I looked up 2.15 on the z-table and got .4842 which is 48.42%. Is this at all in the ball park? I feel like it's completely wrong and not what he's looking for.

Any and all help would be greatly appreciated! :tup:

Data:

3.29

4.99

3.49

3.49

3.89

3.69

3.99

1.99

2.99

4.99

3.29

2.79

4.39

3.29

3.59

6.99

2.99

3.69

3.29

3.19

4.99

2.99

6.69

4.59

2.99