Step 1
Given; Suppose that shoe sizes of American women have a bell-shaped distribution with a mean of 8.04 And a standard deviation of 1.53.
Required; using the empirical rule what percentage of American women have shoe sizes that are less than 11.1. please do not round your answer.
Step 2
The empirical rule states that for a normal distribution, 68% of the distribution are within one standard deviation from the mean, 95% are within two standard deviations from the mean and 99.7% are within three standard deviations from the mean.
Given that:
![\begin{gathered} mean(\mu)=8.04 \\ Standard\text{ deviation\lparen}\sigma)=1.53 \\ \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/taldxy2jb27znb6cwzaw4omsk7ikesksrp.png)
68% are within one standard deviation
![\mu\pm\sigma=8.04\pm1.53=(6.51,9.57)](https://img.qammunity.org/2023/formulas/mathematics/college/cw1afs6g1b2rl09j6z8sg4r39wr9q43prb.png)
95% are within two standard deviation
![\mu\pm2\sigma=8.04\pm2(1.53)=(4.98,11.1)](https://img.qammunity.org/2023/formulas/mathematics/college/z07izldzwxfquzsl90lwzde8qwfqg5tvxc.png)
Thus, we can see that the American women have shoe sizes that are no more than 11.1 will be;
![95\text{\%+\lparen}(100-95)/(2))\text{\%=95+2.5=97.5\%}](https://img.qammunity.org/2023/formulas/mathematics/college/m84w95ztsmv0iozi6cmb26mj9xwfqtwh85.png)
Answer;
![The\text{ American women with a shoe size that are less than 11.1=97.5\%}](https://img.qammunity.org/2023/formulas/mathematics/college/gvagje81qwuadd99ubzx0s66rpue5y98y0.png)