Answer: -2
Step-by-step explanation:
Given : A chef asks for your advice given that you are a student of business statistics.
He tells you that it takes approximately a normally distributed .[tex]\mu=35[/tex] and [tex]\sigma= 2[/tex] to cook a spaguetti and meatball meal.
Let x be a random variable that represents the time to cook a spaguetti and meatball meal.
Using the formula , [tex]z=\dfrac{x-\mu}{\sigma}[/tex] the value of z for x= 31 we get
[tex]z=\dfrac{31-35}{2}=-2[/tex]
Hence, the z-score for 31 minutes = -2
