You are working on the continuing study examining low birthweight infants that your Stats professor keeps talking about. He hands you the dataset and asks you some seemingly simple questions.
First, he wants to know, is there an association between sex of and...
The distribution of a drugs among addicts with autoimmune disorder is N(6.9, 16.81). What is the probability that one of these addicts enters your office and reports taking 16 drugs or more?
The Attempt at a Solution
z = (16-6.9)/4.1 = 2.21
P(z >16) = 0.014 from...
Right, There will be 12.5% between infinity and each Z-score. There is 37.5% between each z-score and the mean
Don't i still look look for .125 making the middle 75% between Z = 1.15 and Z = -1.15. (from z-table)
Therefore, 9.1 - (1.15)(2.14) to 9.1 + (1.15)(2.14) = 6.61 through 11.6 making...
Wait I think I have it now
There will be 12.5% between the mean and each Z-score,so we look for .125. The closest Z is .32, so the middle 75% is between Z = 0.32 and Z = -32.
Therefore, 9.1 - (0.32)(2.14) to 9.1 + (.32)(2.14) = 8.41 through 9.78.
Thank you so much. I think I understand
I want the x value that cuts off the upper 75% of the curve
P(X>x) = 0.75
So I went to the z-table, and got a z value of 0.67 (using 0.251 inside the table, or should i use 0.248)
0.67 = x-9.1/2.14
x= .67(2.14) + 9.1
TO find the kth percentile
=nk/100 (where k=kth percentile and n is the number of observations
n(50)/100 = 9.3
Can n not be an integer?
Then I planned on plugging the n into the formula to solve
for the 75th percentile...
You are asked to estimate of the most common level of a ace-inhibitor taken by patients who take the drug. Give your best estimate of central tendency.
These are the measurements
0.0 12.5 13.6 14.5 12.0 13.2
0.0 0.0 13.1 14.2 12.5...