Answer:
-1
Step-by-step explanation:
Given: Mean= 25 minutes.
Standard deviation= 2 minutes
x= 23 minutes.
Lets find the z-score for the number of sandwiches delivered in less than 23 mins.
Formula: Z-score= 
Z-score= 
⇒ Z-score= 
∴ Z-score will be -1
Hence, -1 is the z-score for the number of sandwiches delivered in less than 23 minutes.
I’m working on something like that now
Combine like terms
9r+r=10r^2
7b+b=8b^2
10+10r^2+8b^2+4n