20*117.98 + 20*124.32 = $4846.00
<span>$4846.00*1.02 = $4942.92 </span>
<span>40*128.48 = $5139.20 </span>
<span>0.02*5139.20 = $102.78 </span>
<span>$5139.20 - $102.78 = $5036.42 </span>
<span>$5036.42 - $4942.92 = $93.50,
So the answer is (B)</span>
Hopefully this helped you.
Answer:
(A) P (D > 0) = 99.38%
(B) P (D > 15) = 10.56%
Step-by-step explanation:
The random variable D = difference, is defined as the difference between the reading test scores after and before the program.
The random variable <em>D </em>follows a normal distribution with mean, and standard deviation, .
(A)
Compute the probability that the children showed any improvement, i.e.
P (D > 0):
Use the standard normal random variable to determine the probability.
The percentage of children showed any improvement is:
0.9938 × 100 = 99.38%
Thus, 99.38% of children showed improvement.
(B)
Compute the probability that the children improved by more than 15 points, i.e. P (D > 15):
Use the standard normal random variable to determine the probability.
The percentage of children improved by more than 15 points is:
0.1056 × 100 = 10.56%
Thus, 10.56% of children showed improvement by more than 15 points.
Answer:
I believe the answer would be $39.49. If I am wrong, plz forgive me! I hope this helps.