Henry has collected data to find that the typing speeds for the students in a typing class has a normal distribution. What is the probability that a randomly selected student has a typing speed of less than 51 words per minute if the mean is 47 words per minute and the standard deviation is 4 words per minute? Use the empirical rule.
- Provide the final answer as a percent.
53
Provide your answer below:

Step 1 ：The empirical rule, also known as the 68-95-99.7 rule, states that for a normal distribution, almost all data falls within three standard deviations of the mean. Under this rule, 68% of the data falls within one standard deviation, 95% falls within two standard deviations, and 99.7% falls within three standard deviations.

Step 2 ：In this case, we are asked to find the probability that a randomly selected student has a typing speed of less than 51 words per minute. The mean is 47 words per minute and the standard deviation is 4 words per minute. This means that a typing speed of 51 words per minute is one standard deviation above the mean.

Step 3 ：According to the empirical rule, 68% of the data falls within one standard deviation of the mean. This means that 34% of the data falls between the mean and one standard deviation above the mean, and another 34% falls between the mean and one standard deviation below the mean.

Step 4 ：Therefore, the probability that a randomly selected student has a typing speed of less than 51 words per minute is the sum of the percentage of data that falls below the mean and the percentage of data that falls between the mean and one standard deviation above the mean.

Step 5 ：Final Answer: The probability that a randomly selected student has a typing speed of less than 51 words per minute is approximately \(\boxed{84\%}\).