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Six different second-year medical students at Bellevue Hospital measured the blo

ID: 3206616 • Letter: S

Question

Six different second-year medical students at Bellevue Hospital measured the blood pressure of the same person. The systolic readings (in mmHg) are listed below. Find the range, variance, and standard deviation for the given sample data. If the subject's blood pressure remains constant and the medical students correctly apply the same measurement technique, what should be the value of the standard deviation?

136 128 149 145 146 136

Range=   mmHg

Sample variance=   mmHg2

(Round to the nearest tenth as needed.)

Sample standard deviation= mmHg (Round to the nearest tenth as needed.)

What should be the value of the standard deviation?

A.

Ideally, the standard deviation would be one because this is the lowest standard deviation that can be achieved.

B.

Ideally, the standard deviation would be zero because all the measurements should be the same.

C.

Ideally, the standard deviation would be one because all the measurements should be the same.

D.

There is no way to tell what the standard deviation should be.

Explanation / Answer

range=max-min=149-128=21 mmHg

sample variance =(318/5)=63.6

std deviation =(63.6)1/2=7.975

B.

Ideally, the standard deviation would be zero because all the measurements should be the same.

X (X-mean)^2 128 144 136 16 136 16 145 25 146 36 149 81 total(T) 840 318 mean=T/6 140