Answer:
a = 9
Step-by-step explanation:
So in this case you just cross multiply
8 : 12 = 6 : a
6(12) = 8(a)
72 = 8a
Divide both sides by 8
a = 9
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
i dknd make some fuing shows broStep-by-step explanation:
C,
{(-1, -3),(0,-1),(1,1),(2,3),(3,5)}