Processing time at our facility can be assumed normally distributed with a mean $15$ minutes and standard deviation $3$ minutes.

What is the probability that a random SAMPLE of $100$ units be processed at our facility with an AVERAGE processing time of between $14$ and $16$ minutes?

How would you calculate the above probability in Excel?

$=$NORMDIST $(16,15,3,$ TRUE$)-$ NORMDIST$(14,15,3,$ TRUE$)$

$=$NORMDIST $(16,15,3/$SQRT$(100),$ FALSE$)-$ NORMDIST$(14,15,3/$SQRT$(100),$ FALSE$)$

$=$NORMDIST $(15,16,3,$ TRUE$)-$ NORMDIST$(15,14,3,$ TRUE$)$

$=$NORMDIST $(16,15,3/$SQRT$(100),$ TRUE$)-$ NORMDIST$(14,15,$

$3/$SQRT$(100),$ TRUE$)$