High School

The weight of male babies less than 2 months old in the United States is normally distributed with a mean of 11.7 pounds and a standard deviation of 2.9 pounds.

(a) Use the TI-84 Plus calculator to determine the proportion of babies that weigh more than 14 pounds.

Answer :

Final answer:

To find the proportion of male babies weighing more than 14 pounds, use the normalcdf function on the TI-84 Plus calculator with the lower bound as 14, upper bound as a large number, mean as 11.7, and standard deviation as 2.9.

Explanation:

To find the proportion of male babies weighing more than 14 pounds when the weights are normally distributed with a mean of 11.7 pounds and a standard deviation of 2.9 pounds, we can use the TI-84 Plus calculator's normal distribution functions. To do this, follow these steps:

  1. Turn on the calculator and press the '2ND' button, then 'VARS' to access the distribution menu.
  2. Select '2: normalcdf' by pressing '2' or scrolling down to it and pressing 'ENTER'.
  3. Enter 14 for 'lower', 1E99 (or some other very large number to represent infinity) for 'upper', 11.7 for 'μ', and 2.9 for 'σ'.
  4. Press 'ENTER' to calculate the proportion.

This will give you the proportion of the area under the normal curve that lies to the right of 14 pounds, which corresponds to babies weighing more than 14 pounds.