Question 511089
Twenty five items are sampled. It is assumed that each of them has the same probability of being defective. The probability that exactly 2 of the 25 are defective could best be found by using which distribution?
a. Normal 
b. Binomial
c. Poisson
d. Exponential
---
Ans: B
--------------------------------------- 
A surgical technique is performed on seven patients. You are told there is a 70% chance of success. Find the probability that the surgery is successful for 3 to 5 patients. 
a. 0.0972
b. 0.6418
c. 0.3177
d. 0.4149 
---
Ans: b
----------------------------------------
On average 3.9 customers arrive every fifteen minutes at Jefferson’s Pub. What is the standard deviation for the number of customers arriving every fifteen minutes?
a. 4.21
b. 1.95
c. 1.97
d. 3.9
Ans: c
==============
Cheers,
Stan H.
===============