Answer:
0.7493 or 74.93%
Step-by-step explanation:
We are given;
Population mean; μ = 100
Population standard deviation; σ = 12
Sample mean 1; x1¯ = 90
Sample mean 2; x2¯ = 120
Z-score formula of the data given is;
z = (x¯ - μ)/σ
z1 = (90 - 100)/12
z1 = -0.83
z2 = (120 - 100)/12
z2 = 1.67
Since we wan to Find the probability that a randomly selected bill is between $90 to $120.
Thus;
P(90 < x¯ < 120) = P(−0.83 < Z < 1.67)
Probability will be gotten from online probability with 2 z-scores calculator to get;
P = 0.7493
I would say it is A because if you subtract <em>p,</em> the original price by $2.50, you would get <em>d, </em>the discounted price. Look at B u see that you're adding the discount which doesn't make sense. Looking at C, the discounted price of different prices can't always be the same. And finally, D, the discounted price is greater than the original. Also, if you subtract you would get different discounts.