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 
100
6738 —> 7000
5903 —> 6000
7000 - 6000 = 1000
Answer:




Step-by-step explanation:
Given

Required
Solve (a) to (d)
Using tan formula, we have:

This gives:

Rewrite as:

Using a unit ratio;

Using Pythagoras theorem, we have:




Take square roots of both sides

So, we have:


Solving (a):

This is calculated as:


Where:


So:




Solving (b):

This is calculated as:

Where:
---- given
So:


Solving (c):

In trigonometry:

Hence:

Solving (d):

This is calculated as:


Where:


So:



Answer:
40 games will be played in total.
Step-by-step explanation:
It reveals whether the answers will be negative, and how many solutions the equation will have.