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mean 8237 and standard deviation 30.2
What is the 2.28th percentile of total passenger weight
2..Suppose the profit from 1000 plays of a poker machine is normally distributed with mean 5.2 and standard deviation 4.2
Be careful with this question you have to look at EVERY option and tick every option that is correct
Which is correct if you want to work out if profit from 1000 plays is in the bottom 2.28%
Select one or more:
a. A profit is in the bottom 2.28% if it is less than -7.40
b. You can use the fact that the 2.28th percentile of the z distribution is -2
c. A profit is in the bottom 2.28% if it is less than -3.2
3..Many students did an exam, the mean was 11 and the standard deviation was 36.
The highest mark was X=137, What is the zscore of the highest mark?
4..Suppose 80% of all people like a product , So if you get a
sample of 100 people the number of people X in the sample that like
the product is binomial with mean of 80 and standard deviation 4,
If there is a sample where 90 out of 100 like the product what is the zscore
in other words find the zscore if x=9 ?
5..Suppose a variable X has sample mean 200 and standard deviation 10
and the variable Y has sample mean 4000 with standard deviation 100
and when you plot the variables X and Y the points form a perfect positive line so
you can predict the future value of Y given a future value of X
using the formula
Future value of Y = mean of Y + standard deviation of Y*(zscore of X)
predict the future value of Y if x is 200.17
6..Suppose 6800 students did an exam so the list of 6800 exam marks is a quantitative variable X. Also suppose the exam mark of 50 is the 1.3th percentile
Be careful with this question tick all correct answers
Select one or more:
a. 1.3% of students got a mark below 50
b. 142 students got a mark below 50
c. 88 students got a mark below 50
d. 98.70% of student got a mark below 50
