assuming  an  approximately  normal  data  set,  find  the  99.7%  confidence  interval  for  systolic  blood  pressure  in  women given  a  sample  size  of  1000  with  a  mean  of  123.4  and  a  standard  deviation  of  19.9.  1.73.65  –  173.15 3.103.5  –  143.3 2.63.7  –  183.1 4.83.6  –  163.2

The correct answer is Choice 2: 63.7 to 183.1

A 99.7% confidence interval translates to the area within 3 standard deviations of the mean. We know the standard deviation is 19.9. Now, just multiply that by 3 and you have 59.7.

Add and subtract that from the mean to find the interval.

123.4 + 59.7 = 183.1
123.4 - 59.7 = 63.7