Andy can pour 9 servings of juice
A sample of size n taken from a population with mean = µ and standard deviation = σ has sample mean = µ and sample s.d. = σ/√n.
If the final exam scores are normally distributed, and X is a random variable for the mean of a sample, then
Pr[X < 70] = Pr[(X - 73) / (7.8/√24) < (70 - 73) / (7.8/√24)]
… ≈ Pr[Z < -1.8842]
… ≈ 0.0298
(where Z is normally distributed with µ = 0 and σ = 1).
To Convert a percentage to a decimal, you divide the percentage number by 100.
6.5% ÷ 100 = .065.
This is the rate you will multiply $14.29 by to get the amount of sales tax you must pay.
The correct answer is (0.065) (14.29) = $0.93
Based on the information provided, none of the above options are correct.
The options provided would make more sense if it were a 6 3/4% tax, and the answer would be B.