Answer:
0.13% of students have scored less than 45 points
Step-by-step explanation:
Problems of normally distributed samples can be 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:

About what percent of students have scored less than 45 points?
This is the pvalue of Z when X = 45. So



has a pvalue of 0.0013
0.13% of students have scored less than 45 points
(-3).
We plug (-1) for x in g(x) and we get:
(-1) - 2(-1)^2.
To simplify, (-1)^2 turns to just 1. since a negative times a negative gives a positive.
Then, we have (-1) - 2(1) or (-1) - 2 or -1 - 2.
This is then -3
15-6.9=8.1
8.1 x 3.9= 31.59
$31.59 is your answer
hope this helps :)
You follow the same steps as you would normally, but you can count how many units down it is, instead of how far up.