Approximate the following binomial probabilities by the use of ...

[Starlight]

Approximate the following binomial probabilities by the use of normal approximation. Eight percent of customers of a bank keep a minimum balance of 500 in their checking accounts. What is the probability that in a random sample of 100 customers
 a. exactly 6 keep the minimum balance of 500?
  b. exactly 11 keep the minimum balance of 500?
  c. 6 or fewer keep the minimum balance of 500?
  d. 5 or more keep the minimum balance of 500?
  e. 10 or fewer keep the minimum balance of 500?
  f. 11 or fewer keep the minimum balance of 500?

Question 2

In a residual plot against x that does not suggest we should challenge the assumptions of our regression model, we would expect to see a
 a. horizontal band of points centered near zero.
 b. widening band of points around the x-axis.
  c. band of points having a slope consistent with that of the regression equation.
  d. parabolic band of points centered at the origin.

[aidanmbrowne]

Answer to Question 1

a. 0.1124
b. 0.0803
c. 0.2912
d. 0.9015
e. 0.8212
f. 0.9015

Answer to Question 2

a