Final answer:
To estimate the proportion of horses with stomach distress who are fed at least two flakes of alfalfa per day and determine the margin of error, a confidence interval can be used. The margin of error in this case is 0.136.
Step-by-step explanation:
To estimate the proportion of horses with stomach distress who are fed at least two flakes of alfalfa per day, the veterinarian can use a confidence interval.
To find the margin of error for a 99% confidence interval, the formula is:
Margin of Error = Z * sqrt(p(1-p)/n)
where Z is the Z-score for a 99% confidence level, p is the proportion from the sample, and n is the sample size.
In this case, the sample proportion is 42/62, and you can use a Z-score of 2.576 for a 99% confidence level. Plugging in these values, the margin of error is:
Margin of Error = 2.576 * sqrt((42/62)(1-42/62)/62) = 0.136