Pizza delivery times at Pizza Time are normally distributed with a mean time of 27 minutes and a standard deviation of 3 minutes. Approximately what percent of pizzas are delivered between 24 and 30 minutes?

Question

karissafrazier · Answer

XD bro i'm pretty sure u gotta multiply it

karissafrazier · Answer

nah bro u don't do either- if u subtract you'll get a negitive answer and we don't want that, if u add it you won't get the right answer (i had this question once) so u multiply or divide- if u divide it all together i'm pretty sure u get a big number- so multiply but hey u heard it from a stupid freshman XD

karissafrazier · Answer

https://www.youtube.com/watch?v=igpVebLCD8k

Vocaloid · Answer

First, calculate the z-score for each boundary value (24 minutes and 30 minutes)

Z-score formula:

$$z=\frac{ x-μ }{ σ}$$
where z is the z-score, x is the value being examined, μ is the mean, and σ is the standard deviation. first, plug in x = 24, along with the mean and standard deviation, and calculate the z-score. repeat with x = 30.

then, once you have your z-scores, use a z-table or calculator to calculate the associated probability for each z-score. subtract the two probabilities to get the area between the two values.

Vocaloid · Answer

Alternative method: This is a special case in which your boundary values are exactly +1/-1 SD below and above the mean, so you can use the empirical rule to find the area. https://calcworkshop.com/wp-content/uploads/normal-distribution-curve.png