The mean weight of a heard of white-tailed deer is 140.3 pounds, with a standard deviation of 7.2 pounds. What is the probability that a randomly selected deer will weigh less than 149 pounds?(1 point) Responses 16.7% 16.7% 11.3% 11.3% 83.3% 83.3% 88.7%

1 answer

To find the probability that a randomly selected white-tailed deer will weigh less than 149 pounds, we can use the Z-score formula. The Z-score tells us how many standard deviations a specific value is from the mean.

The Z-score is calculated as follows:

\[ Z = \frac{(X - \mu)}{\sigma} \]

where:

  • \(X\) is the value we are interested in (149 pounds),
  • \(\mu\) is the mean weight (140.3 pounds),
  • \(\sigma\) is the standard deviation (7.2 pounds).

Plugging in the values:

\[ Z = \frac{(149 - 140.3)}{7.2} = \frac{8.7}{7.2} \approx 1.2083 \]

Next, we look up the Z-score of approximately 1.21 in the standard normal distribution table (or use a calculator or software that provides the cumulative distribution function for the normal distribution).

Looking up the Z-score of 1.21 typically gives us approximately 0.8869 or 88.69%.

So, the probability that a randomly selected deer will weigh less than 149 pounds is about 88.7%.

The correct response is 88.7%.