The weight of the average 18-year-old male is 163.5 pounds with a standard deviation of 10.5 pounds. Which of the following statements is true with a 95% confidence?
When I did this, I got 132 and 195 pounds.

Question

The weight of the average 18-year-old male is 163.5 pounds with a standard deviation of 10.5 pounds.  Which of the following statements is true with a 95% confidence?
When I did this, I got 132 and 195 pounds.

anonymous · Answer

Oh wait. It should be 142.5 and 184.5, right?

amistre64 · Answer

95% is most accuratly defined as a z score of 1.96;  the emipirical rule is an approximation of 2

$$95\% \approx 163.5\pm2(10.5)$$
$$95\% = 163.5\pm1.96(10.5)$$

amistre64 · Answer

the 184.5 is good