Question

Birth Weights. The WONDER database, maintained by the Centers for Disease Control and Prevention, provides a single point of access to a wide variety of reports and numeric public health data. From that database, we obtained the following data for one year's birth weights of male babies who weighed under 5000 grams (about 11 pounds).

a. Obtain a relative-frequency histogram of these weight data.

b. Based on your histogram, do you think that, for the year in question, the birth weights of male babies who weighed under $5000$grams are approximately normally distributed? Explain your answer.

Short answer

a. The relative-frequency histogram of the given weighted data is:

b. No, the birth weights of male babies who weighed under $5000$grams are approximately not normally distributed.

Step-by-step solution

Part (a) Step 1: Given Information

Given frequency distribution table is:

For the given data, create a relative frequency histogram.

Part (a) Step 2: Explanation

Formula used:

The relative frequency is calculated using the following formula:

$\text{Relative frequency}=\frac{\text{Frequency}}{\text{Sum of frequencies}}$

Calculation:

The following formula can be used to calculate relative frequencies for the given frequency distribution:

The relative frequency histogram can now be made as follows:

Part (b) Step 1: Given Information

Determine whether or not the birth weight of male newborns weighing less than 500 grammes is typically distributed.

Part (b) Step 2: Explanation

The data values in the histogram created in the previous section are on the left side of the plot, indicating that it is skewed to the left. As a result, it's possible to conclude that the birth weights of male babies weighing less than 500 grams are not evenly distributed.