57 408
Assignments Done
Successfully Done
In February 2018
Your physics homework can be a real challenge, and the due date can be really close — feel free to use our assistance and get the desired result.
Be sure that math assignments completed by our experts will be error-free and done according to your instructions specified in the submitted order form.
Our experts will gladly share their knowledge and help you with programming homework. Keep up with the world’s newest programming trends.

Answer on Statistics and Probability Question for Chris

Question #4365
The average length of a hospital stay for all diagnoses is 4.8 days. If we assume that the lengths of hospital stays are normally distributed with a variance of 2.1, then 10% of hospital stays are longer than how many days? Thirty percent of stays are less than how many days?
Expert's answer
First let's calculate the standard deviation.
Variance = (standard deviation)^2
Standard deviation = sqrt(2.1)
Standard Deviation = 1.45
Now we must use z-scores. To find the top 10% of hospitals, we must find the z-score that corresponds to 90%. Looking at a z-score table, we look for 0.9000 and can find this z-score to be about 1.28. Then with the formula for z-scores, we can find the corresponding value.

z = (x-μ)/σ
1.28 = (x-4.8)/1.45
x = 6.656

Thus 10% of hospital stays are longer than 6.656 days.
To find the lowest 30% we can look for 0.3000 and can find this z-score to be about -0.525. Then again with the z-score formula we have:

-0.525 = (x-4.8)/1.45
x = 4.03875

Thus 30% of stays are less than 4.03875 days.

Need a fast expert's response?

Submit order

and get a quick answer at the best price

for any assignment or question with DETAILED EXPLANATIONS!


Assignment Expert
01.07.2015 11:36

Dear Anon.
Both variance and standard deviation are applied in statistics . Besides, you can see all calculations involve a standard deviation, not variance.

01.07.2015 01:57

That damn variance got me. Forgot to turn it into a standard deviation!

Leave a comment

Ask Your question