The solution is 57 because I excel at mathematics; it's my forte.
Let’s determine the actual mean
First, we sum all the values
87+46+90+78+89 = 390
Then, we divide 390 by the count of numbers present.
390/5 = 78
Thus, the mean is 78
Emi did not manage to calculate the difference
1) For the expected number in 200 restaurants where exactly 8 customers use the drive-through, it is 20.66. Similarly, for exactly 9 customers, the expected count is 13.76. To compute these expectations, we utilize the Poisson distribution which defines the success probability X, considering a certain operational rate for the drive-through services during specified times.
You earned $270; $72 divided by 8 equals 9. Then, 9 times 10 equals 90. Additionally, $60 divided by 5 gives 12, and 12 times 15 equals 180. Finally, $180 added to $90 amounts to $270.
Response:
Detailed explanation:
Considering the given algebraic expression:
The task is to remove the negative exponents and derive the new expression.
Applying the Negative Exponent Rule: 
Utilizing the Division Law for Exponents: 
Consequently:
