Question

Pay your bills: In a large sample of customer accounts, a utility company determined that the average number of days between when a bill was sent out and when the payment was made is 26 with a standard deviation of 5 days. Assume the data to be approximately bell-shaped. Part: 0/3 Part 1 of 3 (a) Between what two values will approximately 95% of the numbers of days be? and Approximately 95% of the customer accounts have payment made between days.

Answer 1

Solution :

Given that ,

mean = $\mu$ = 26

standard deviation = $\sigma$ = 5

Using Empirical rule,

P( $\mu$ - 2$\sigma$ < x <  $\mu$ + 2$\sigma$ ) = 95%

= P( 26 - 2 * 5 < x < 26 + 2 * 5 ) = 95%

= P( 26 - 10 < x < 26 + 10 ) = 95%

=P( 16 < x < 36) = 95%

Approximately 95% of the customer accounts have payment made between 16 and 36 days

Answer 2

28 & 36