Answer :
Answer:
[tex] z=\frac{x- \mu}{\sigma}[/tex]
And replacing we got:
[tex] z=\frac{425-500}{75}= -1[/tex]
And we can calculate this probabilit using the normal standard distribution or excel and we got:
[tex] P(z<-1)= 0.159[/tex]
Step-by-step explanation:
If we define the random variable of interest "the amount spent by a family of four of food per month" and we know the following parameter:
[tex] \mu = 500, \sigma = 75[/tex]
And we want to find the following probability:
[tex] P(X<425)[/tex]
And we can use the z score formula given by:
[tex] z=\frac{x- \mu}{\sigma}[/tex]
And replacing we got:
[tex] z=\frac{425-500}{75}= -1[/tex]
And we can calculate this probabilit using the normal standard distribution or excel and we got:
[tex] P(z<-1)= 0.159[/tex]