In statistics, if a problem asks for the sensitivity, specificity or accuracy or a test, you just need the following formulas:

Sensitivity = (true positives)/(true pos. + false neg)

Specificity = (true negatives)/(true neg. + false pos)

Accuracy = (true negative + true positive)/total

These values are generally easy to find given a 2 x 2 matrix with the data for the problem

## Monday, March 28, 2016

## Tuesday, March 15, 2016

with a mean of 200 pounds and a standard deviation of 25 pounds.

Find the probability that a randomly selected professional baseball

player has a weight less than 225 pounds, P(x < 225) - ?

Z value is (x-mean)/standard deviation

x = 225

mean= 200

standard deviation = 25

Z = (225 - 200)/25 = 1

Now look up Z(1) on the chart and you will see it is .8413. That is the answer since they are asking for P(x < 225) if it was P(x > 225) then would have to take 1- .8413

Subscribe to:
Posts (Atom)