SOLUTION: If anyone can help me answering this question would be greatly appreciated The speed of all cars traveling on a highway is normally distributed with a mean of 68 miles per hour

Algebra.Com
Question 871457: If anyone can help me answering this question would be greatly appreciated
The speed of all cars traveling on a highway is normally distributed with a mean of 68 miles per hour and a standard deviation of 3 miles per hour. Find the probability that the mean speed of random sample of 16 cars traveling on the highway is:
a) less than 66mph
b) more than 69mph
c) between 67 and 69mph
Answer by ewatrrr(24785)   (Show Source): You can put this solution on YOUR website!


Hi

m = 68mph, SD = 3,  s = 3/sqrt(16) = 3/4

sample 16 

a) P(xbar < 66mph), z = -2/(3/4) = -8/3 = -2.6667

P(z < -2.6667) = .0038   0r  .38%

b)P(xbar > 69mph), z = 1/(3/4) = 4/3

P(z > 1.3333) = .0912   0r 9.12%

P( 67 < xbar <69 ) = .9088 - .0912 = .8976   0r 89.76%

0r P( 67 < xbar <69 )= normalcdf(67, 69, 68, .75) 

RELATED QUESTIONS


Any help on this question would be greatly appreciated. The assignment is due on April 9,  (answered by josgarithmetic,ikleyn)

I know this is a combinatorial type of question, however, I am still baffled, your help... (answered by jrfrunner,scott8148)

I need help answering this question. Will someone please help? Thank you

Describe what  (answered by vleith)

Please Help with this question urgently....:(

The speed of motorists on a highway is... (answered by Theo)

If anyone could help me out it would be greatly appreciated. I am stumped here and would... (answered by MathLover1)

Hi, everyone. Can anyone help me with this question, please?

The area of a regular... (answered by Alan3354)

please help me on this word question. A car is traveling at a speed of 55 miles per hour,  (answered by ankor@dixie-net.com)

I have been working on my homework all day and this may be the simplest of problems but I  (answered by stanbon)

Hi, everyone. Can anyone help me with this question, please?

Find the measure of each... (answered by Theo)