We know that the empirical rule states that 99.7% of the area is in the interval:
![(\mu-3\sigma,\mu+3\sigma)](https://img.qammunity.org/2023/formulas/mathematics/college/w9nbz52uxh6ap0zhh0xggs2c9sjj3f2kpj.png)
In this case we notice that we are looking at the interval (56,89) in a normal distribution with mean 56 and standard deviation 11, which means that we area in the interval:
![(\mu,\mu+3\sigma)](https://img.qammunity.org/2023/formulas/mathematics/college/4nx208yp0cwak8fh1wkvebzsepv9qcei2h.png)
which means that we have half the area of the interval mentioned before. Therefore, the approximate percentage between 56 and 89 is 49.85%