The first-serve percentage of a tennis player in a match is normally distributed with a standard deviation of 4.3%. If a sample of 15 random matches of the player is taken, the mean first-serve percentage is found to be 26.4%. What is the margin of error of the sample mean? please provide explination
We shall use the z-table to solve for the margin of error. The formula for the margin of error is [tex]E=z_{\alpha /2}\cdot \frac{\sigma }{\sqrt{n}}[/tex]
The value of z will be taken with the assumption that the significance level is 5%. So, α=0.025. Then [tex]z_{\alpha \:/2}=1.96[/tex].
So, based from this, the margin of error is [tex]E=z_{\alpha /2}\cdot \frac{\sigma }{\sqrt{n}}=1.96\cdot \frac{0.043}{\sqrt{15}}=0.02[/tex]
