The typical average waiting time at the drive

$-$

thru of a fast food restaurant

$($

measured from the time the order is placed until the order is received

$)$

$$is

$84\mathrm{.}3$

seconds. A manager implements a new drive

$-$

thru system that she hopes will reduce

the wait time for orders. In a sample of

$25$

$$orders placed using the new system the

average wait time was

$78\mathrm{.}9$

$$seconds with a standard deviation of

$9\mathrm{.}2$

$$seconds$.$

a

$)$

$$At the

$\mathrm{.}01$

$$level did the new system reduce the average wait time?

b

$)$

$$Based on the answer for a

$)$

$$what seems to be the reason for the reduced average

wait time?

c

$)$

$$Do we know for certain that the reasonstats exam $4$ MW late $($spring $2024)$ Name Eduord Redriguez

$(17)1.$ The typical average waiting time at the drive$-$thru of a fast food restaurant

$($measured from the time the order is placed until the order is received$)$ is $84\mathrm{.}3$

seconds. A manager implements a new drive$-$thru system that she hopes will reduce

the wait time for orders. In a sample of $25$ orders placed using the new system the

average wait time was $78\mathrm{.}9$ seconds with a standard deviation of $9\mathrm{.}2$ seconds.

a$)$ At the $\mathrm{.}01$ level did the new system reduce the average wait time?

b$)$ Based on the answer for a$)$ what seems to be the reason for the reduced average

wait time?

c$)$ Do we know for certain that the reason given in part b$)$ is why the wait time was

reduced?

d$)$ If I did a sample of $20$ orders and found a mean wait time of $79\mathrm{.}4$ seconds would

that be something you would expect based on the problem?