Question

In: Statistics and Probability

QUESTION 13 A normally distributed population has a mean of 98.47 and a standard deviation of...

QUESTION 13

A normally distributed population has a mean of 98.47 and a standard deviation of 0.45. Determine the sample avergage that is the third quartile for samples of size 195.

Round to the nearest hundredth

QUESTION 14

A normally distributed population has a mean of 112 and a standard deviation of 24. Determine the value of the sample average at the 25th percentile for samples of siz 140.

Round to the nearest tenth

QUESTION 15
A normally distributed population has a mean of 95 and a standard deviation of 23. Determine the value of the sample average at the 75th percentile for samples of siz 61.

Round to the nearest tenth

Solutions

Expert Solution

Answer 13

given that mean = 98.47, standard deviation = 0.45, sample size n = 195 and z score for third quartile or 75th percentile is 0.674 (using percentile table)

using the formula , x(bar) is the required sample mean

this implies

Answer 14

given that mean = 112, standard deviation = 24, sample size n = 140 and z score for 25th percentile is -0.674 (using percentile table)

using the formula , x(bar) is the required sample mean

this implies

Answer 15

given that mean = 95, standard deviation = 23, sample size n = 61 and z score for 75th percentile is 0.674 (using percentile table)

using the formula , x(bar) is the required sample mean

this implies


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