Answer:
a) 0.7734
Step-by-step explanation:
Problems of normal distributions 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 question, we have that:

(a) what proportion of children aged 13 to 15 years old have scores on this test above 83 ?
This is 1 subtracted by the pvalue of Z when X = 83. So



has a pvalue of 0.2266
1 - 0.2266 = 0.7734
The answer is 0.7734
Answer:
hol on im finna learn about it then answer
Step-by-step explanation:
...
Y=4x because 20/5 equals 4
(12 * 7 + n)8=12.5
(12 * 7 + n)= 100
N= 16. The new number will be 16. Hope this helps. :)
Answer:
12√5
Step-by-step explanation:
According to the attached sketch, there are 2 triangles which we need to focus on, triangle A (in yellow) and triangle B (In red).
If you look at triangle A, we notice that X is the hypotenuse of triangle A. This means that X must be the largest length in triangle A, hence we can say that x must be greater than 24 (or 24 < x)
Now look at triangle B, in this case, they hypotenuse is 30 and x is the length of one of the sides. This means that x must be shorter than the hypotenuse (i.e x < 30)
from the 2 paragraphs above, we can see now that we can assemble an inequality in x
24 < x < 30
If we look at the choices, we can immediately ignore 33 because x must be less than 30,
working out the choices, we find that the only choice which falls into the range 24<x<30 is the 2nd choice 12√5 (= 26.83) (which is the answer)
The last 2 choices give values smaller than 24 and are hence cannot be the answer