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In: Statistics and Probability

The random variable x is normally distributed with a mean of 68 and a standard deviation...

The random variable x is normally distributed with a mean of 68 and a standard deviation of 4. Find the interquartile range (IQR)? Use R.

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Expert Solution

========================================CODE======================================

# First to find out Third Quartile with mean 68 and Standard deviation 4

Q3=qnorm(p = 0.75 ,mean = 68 ,sd = 4)     # Third Quartile
Q3

Q1=qnorm(p = 0.25 ,mean = 68 ,sd = 4) # First Quartile
Q1

IQR =Q3 -Q1                           # Inter quartile range
IQR

======================================OUTPUT========================================

> Q3=qnorm(p = 0.75 ,mean = 68 ,sd = 4) # Third Quartile
> Q3
[1] 70.69796
>
> Q1=qnorm(p = 0.25 ,mean = 68 ,sd = 4) # First Quartile
> Q1
[1] 65.30204
>
> IQR =Q3 -Q1                           # Inter quartile range
> IQR
[1] 5.395918


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