Answer:
a) 95% of the widget weights lie between 29 and 57 ounces.
b) What percentage of the widget weights lie between 12 and 57 ounces? about 97.5%
c) What percentage of the widget weights lie above 30? about 97.5%
Step-by-step explanation:
The empirical rule for a mean of 43 and a standard deviation of 7 is shown below.
a) 29 represents two standard deviations below the mean, and 57 represents two standard deviations above the mean, so, 95% of the widget weights lie between 29 and 57 ounces.
b) 22 represents three standard deviations below the mean, and the percentage of the widget weights below 22 is only 0.15%. We can say that the percentage of widget weights below 12 is about 0. Equivalently we can say that the percentage of widget weights between 12 an 43 is about 50% and the percentage of widget weights between 43 and 57 is 47.5%. Therefore, the percentage of the widget weights that lie between 12 and 57 ounces is about 97.5%
c) The percentage of widget weights that lie above 29 is 47.5% + 50% = 97.5%. We can consider that the percentage of the widget weights that lie above 30 is about 97.5%
