Answer:
Explanation:
The z-score associated with the upper boundary of of this price range is -0.25.
Explanation:
It is provided that the board of directors for Cosmic Coffee wants to know the price range for the lowest 40% of drink sales.
If X represents the price range of drink sales, then
P (X < x) = 0.40
Consider that X follows a Normal distribution.
To compute the probability of a normally distributed random variable we need to first convert the raw score to the z-scores.
The formula to z-score is:
Then,
P (X < x) = 0.40
⇒ P (Z < z) = 0.40
The value of z for this probability is:
z = -0.25
*Use a z-table.
Thus, the z-score associated with the upper boundary of of this price range is -0.25.