68%
Explanation:[tex]\begin{gathered} \text{mean = }\mu\text{ = 27} \\ \text{standard deviation = }\sigma\text{ = 5} \end{gathered}[/tex]
Using the empirical formula of normal distribution:
[tex]\begin{gathered} 68\text{ \% of the data fall within }1\text{ standard deviation of the mean} \\ 95\text{ \% of the data fall within 2 standard deviation of the mean} \\ 99.7\text{ of the data fall within 3 standard deviation of the mean} \end{gathered}[/tex][tex]\begin{gathered} x\text{ is betw}en\text{ 22 and 32, we are looking for the percentage} \\ 32\text{ = }27\text{ + 5} \\ 22\text{ = 27 - 5} \end{gathered}[/tex][tex]\begin{gathered} \text{This can be written as: } \\ \text{32 = }\mu\text{ + 1}\sigma \\ 27\text{ = }\mu\text{ - 1}\sigma \\ \text{ 27 < x < 32 = }\mu\text{ - 1}\sigma\text{ < x < }\mu\text{ + 1}\sigma \\ 68\text{ \% of the customer accounts have payment made betw}en\text{ 22 and 32 days} \end{gathered}[/tex]
