I have a problem dealing with finding a desired percentage and I'm only familiar with finding these kinds of probabilities with a standard deviation and sample mean present. I believe I need to utilize the Z-scores to find this probability but I'm not sure how to get started. Any guidance to get me in the right direction would be great.

Here is the problem:

In 2017,6% of the flights were delayed. Suppose that a random sample of 80 of the flights for the first month of 2018 is selected. What is the probability that, in this sample, the percentage of delayed flights is less than 4%? Assume that the airline’s on time performance rate for the first month of 2018 is the same as it was in 2017.

Here is the problem:

In 2017,6% of the flights were delayed. Suppose that a random sample of 80 of the flights for the first month of 2018 is selected. What is the probability that, in this sample, the percentage of delayed flights is less than 4%? Assume that the airline’s on time performance rate for the first month of 2018 is the same as it was in 2017.

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