Answer:
a) The mean is 
b) The standard deviation is 
Step-by-step explanation:
Normal Probability Distribution:
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.
The probability a student selected at random takes at least 55.50 minutes to complete the examination equals 0.6915.
This means that when X = 55.5, Z has a pvalue of 1 - 0.6915 = 0.3085. This means that when 
So




The probability a student selected at random takes no more than 71.52 minutes to complete the examination equals 0.8997.
This means that when X = 71.52, Z has a pvalue of 0.8997. This means that when 
So




Since we also have that 





Question
The mean is 
The standard deviation is 
Answer:
One has 4 sides and one has 3 sides
Step-by-step explanation:
a square has 4 sides and an equilateral triangle has 3 sides
In the inverse we replace the place of x by y .
![g(x) = \sqrt[3]{x} - 3 \\ \\ x = \sqrt[3]{y} - 3 \\ \sqrt[3]{y} = x + 3 \\ y = {(x + 3)}^{3} \\ y = {(x + 3)}^{2} (x + 3) \\ y = ({x}^{2} + 6x + 9)(x + 3) \\ \\ y = {x}^{3} + 6 {x}^{2} + 9x + 3 {x}^{2} + 18x + 27 \\ \\ y = {x}^{3} + 9 {x}^{2} + 27x + 27 \\ \\ \\ g(x)^{ - 1} = {x}^{3} + 9 {x}^{2} + 27x + 27](https://tex.z-dn.net/?f=g%28x%29%20%3D%20%20%5Csqrt%5B3%5D%7Bx%7D%20%20-%203%20%5C%5C%20%20%5C%5C%20x%20%3D%20%20%5Csqrt%5B3%5D%7By%7D%20%20-%203%20%5C%5C%20%20%5Csqrt%5B3%5D%7By%7D%20%20%3D%20x%20%2B%203%20%5C%5C%20y%20%3D%20%20%7B%28x%20%2B%203%29%7D%5E%7B3%7D%20%20%5C%5C%20y%20%3D%20%20%7B%28x%20%2B%203%29%7D%5E%7B2%7D%20%28x%20%2B%203%29%20%5C%5C%20y%20%3D%20%20%28%7Bx%7D%5E%7B2%7D%20%20%2B%206x%20%2B%209%29%28x%20%2B%203%29%20%5C%5C%20%5C%5C%20%20y%20%3D%20%20%7Bx%7D%5E%7B3%7D%20%20%2B%206%20%7Bx%7D%5E%7B2%7D%20%20%2B%209x%20%2B%203%20%7Bx%7D%5E%7B2%7D%20%20%2B%2018x%20%2B%2027%20%5C%5C%20%20%5C%5C%20y%20%3D%20%20%7Bx%7D%5E%7B3%7D%20%20%2B%209%20%7Bx%7D%5E%7B2%7D%20%20%2B%2027x%20%2B%2027%20%5C%5C%20%20%20%5C%5C%20%5C%5C%20g%28x%29%5E%7B%20-%201%7D%20%20%3D%20%20%7Bx%7D%5E%7B3%7D%20%20%2B%209%20%7Bx%7D%5E%7B2%7D%20%20%2B%2027x%20%2B%2027%20)
I hope I helped you^_^
Yes it is proportional for a table