Answer:
62.17% probability that a randomly selected exam will require more than 15 minutes to grade
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

What is the probability that a randomly selected exam will require more than 15 minutes to grade
This is 1 subtracted by the pvalue of Z when X = 15. So



has a pvalue of 0.3783.
1 - 0.3783 = 0.6217
62.17% probability that a randomly selected exam will require more than 15 minutes to grade
I am gonna assume the answer is 8.If not another 4 i wish you could see the whole picture
Answer:
<h2>d = 8</h2><h2>g = 2</h2>
Step-by-step explanation:
8d + 4 = 5d + 28
Group like terms
That's
8d - 5d = 28 - 4
3d = 24
Divide both sides by 3
d = 8

Cross multiply
we have
7(7g + 8) = 38.5(4)
49g + 56 = 154
49g = 154 - 56
49g = 98
Divide both sides by 49
g = 2
Hope this helps you