I think it’s either A or C
Answer:
171 newspapers.
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:

How many newspapers should the newsstand operator order to ensure that he runs short on no more than 20% of days
The number of newspapers must be on the 100-20 = 80th percentile. So this value if X when Z has a pvalue of 0.8. So X when Z = 0.84.




So 171 newspapers.
Answer: 1 in 13
Step-by-step explanation:
Yes
Here we are finding x, given the angle and adjacent side. To find x we will use the function cos as cos = a/h.
So let's do cos(35°) = 15cm / x
cos(35°) = 0.8 (1 dp)
x = 15 cm / cos(35°)
x = 18.3 cm (1 dp)