Final answer:
Using the empirical rule for normal distributions, approximately 68% of the data falls within one standard deviation of the mean. Therefore, in a group of 20 bags of pet food with a normal distribution, about 14 bags are expected to be within one standard deviation from the mean.
Step-by-step explanation:
The question involves the concept of a normal distribution in statistics, and specifically, how it applies to the weights of bags of pet food. Given that the bags have a mean weight of 50 lb and a standard deviation of 0.2 lb, we can use the empirical rule (68-95-99.7 rule) for normal distributions. This rule states that approximately 68% of the data in a normal distribution falls within one standard deviation of the mean.
In this scenario, we have a group of 20 bags of pet food. To find out how many bags we would expect to fall within one standard deviation from the mean, we would calculate 68% of 20:
Expected number of bags within one standard deviation = 0.68 × 20 = 13.6
Rounding to the nearest whole number, we can expect about 14 bags to fall within one standard deviation from the mean.