Answer: 0.0898
Step-by-step explanation:
Probability = 
Given : Sample size : 528
Number pf customers say they are happy = 237
Probability of getting one happy customer= 
Probability of getting second happy customer=
[subtract 1 from both numbers]
Probability of getting third happy customer=
If 3 customers are elected without replacement
The probability they will all say they are happy with the service =

Hence, the required probability = 0.0898
1. 56.4
2.107.15
So for the first one I subtracted like this:53.41- -2.99=56.4
You may be wandering why i subtracted that way,I did that because you are meant to subtract and the second number already has a negative sign which is MINUS.
And for the second I subtracted the smaller number from the bigger number this way:144.96 ‐ 37.8
Hope this helps...
The reciprocal of 6/7 is 7/6