Answer:the z score is - 1
Step-by-step explanation:
Assuming a normal distribution for the delivery time of sandwiches by Sammy's Sandwich Shop. We would apply the formula for normal distribution which is expressed as
z = (x - u)/s
Where
x = delivery times
u = mean delivery time
s = standard deviation
From the information given,
u = 25 minutes
s = 2 minutes
We want to determine the z-score for the number of sandwiches delivered in less than 23 minutes. It becomes
z = (23 - 25)/2 = - 1
Take the root of both sides and solve.<span>x=<span><span>25</span>+<span><span>10<span>−−</span>√</span>5</span></span>,<span><span>25</span><span>−<span><span>10<span>−−</span>√</span>5</span></span></span></span><span>x≈1.03245553,<span>−0.23245553</span></span>