The IQR is the range of the box in the box and whisker plot
So if you remember how to do the average of something you are already there
You need 2 numbers
First being the lower quartile and upper quartile
48 is where the lower quartile starts and 70 is where the upper quartile finishes *NEVER USE MEDIAN IN IQR
all you have to do is subtract
70-40 and you get as an answer 22.0 being A as your answer
Answer:
The 95% confidence interval for the mean change in blood pressure,
, is 1.744 <
< 2.816
Step-by-step explanation:
The parameters given are;
The number of people in the sample, n = 9
The average drop in blood pressure,
= 2.28 points
The standard deviation, σ = 0.82
The confidence level = 95%
The formula for confidence interval with a known mean is given as follows;

Where:
= z - score at 95% confidence level = 1.96
We therefore have;

Which gives the 95% confidence interval for the mean change in pressure,
, is given as follows;
1.744 <
< 2.816
As the front approaches, you will have a storm.
I hope this helps!