I am needing the following questions answered for my business statistics class.
Each answer needs work shown.
There will be two files they are in excel and each file has 5 or 6 questions they are located on separate tabs displayed at the bottom of the excel worksheet. 
Ashley Langer
Business Stats
Module 4 Homework Problems
Chapter 6
Given a standardized normal distribution (with a mean
of 0 and a standard deviation of 1, as in Table E.2), what is
the probability that

a. Z is less than 1.57?
b. Z is greater than 1.84?
c. Z is between 1.57 and 1.84?
d. Z is less than 1.57 or greater than 1.84?
Given a normal distribution with µ= 100 and ?= 10	
what is the probability that	
	
a.	x > 75
b.	x < 70
c. 	x < 80 or X > 110
d. Between what two X values (symmetrically distributed	
around the mean) are 80% of the values?	
In 2008, the per capita consumption of coffee in the
United States was reported to be 4.2 kg, or 9.24 pounds (data
extracted from en.wikipedia.org/wiki/List_of_countries_
by_coffee_consumption_per_capita). Assume that the per
capita consumption of coffee in the United States is approximately
distributed as a normal random variable, with a mean
of 9.24 pounds and a standard deviation of 3 pounds.

a. What is the probability that someone in the United States
consumed more than 10 pounds of coffee in 2008?
b. What is the probability that someone in the United States
consumed between 3 and 5 pounds of coffee in 2008?
c. What is the probability that someone in the United States
consumed less than 5 pounds of coffee in 2008?
d. 99% of the people in the United States consumed less
than how many pounds of coffee?
Consumers spend an average of $21 per week in cash
without being aware of where it goes (data extracted from
“Snapshots: A Hole in Our Pockets,” USA Today, January
18, 2010, p. 1A). Assume that the amount of cash spent
without being aware of where it goes is normally distributed
and that the standard deviation is $5.

a. What is the probability that a randomly selected person
will spend more than $25?
b. What is the probability that a randomly selected person
will spend between $10 and $20?
c. Between what two values will the middle 95% of the
amounts of cash spent fall?
A statistical analysis of 1,000 long-distance telephone
calls made from the headquarters of the Bricks and Clicks
Computer Corporation indicates that the length of these
calls is normally distributed, with µ= 240 seconds and
 ?= 40seconds.

a. What is the probability that a call lasted less than 180
seconds?
b. What is the probability that a call lasted between 180 and
300 seconds?
c. What is the probability that a call lasted between 110 and
180 seconds?
d. 1% of all calls will last less than how many seconds?


Ashley Langer
Business Stats
Module 4 Homework Problems
The following table contains the probability			
distribution for the number of traffic accidents			
daily in a small city:			
			
Number of Accidents Daily (X) P1X = xi2			
0 0.10			
1 0.20			
2 0.45			
3 0.15			
4 0.05			
5 0.05			
			
"a. Compute the mean number of accidents per day.
b. Compute the standard deviation."		a.	1.85
		b. 	2.0575
If n=5 and p = 0.40,what is the probability that	
a.	x = 4?
b.	x ? 3?
c.	x < 2?
d.	x > 1?
When a customer places an order with Rudy’s On-								
Line Office Supplies, a computerized accounting information								
system (AIS) automatically checks to see if the								
customer has exceeded his or her credit limit. Past records								
indicate that the probability of customers exceeding their								
credit limit is 0.05. Suppose that, on a given day, 20 customers								
place orders. Assume that the number of customers								
that the AIS detects as having exceeded their credit limit is								
distributed as a binomial random variable.								
								
a. What are the mean and standard deviation of the number							a. 	Mean = 1
of customers exceeding their credit limits?								SD= 0.9747
b. What is the probability that zero customers will exceed								
their limits?							b.	
c. What is the probability that one customer will exceed his								
or her limit?							c.	P(x=1) = 20C1 (0.05)^1 (0.95)^19 = 20 (0.05) (0.95)^19 = 0.3774
d. What is the probability that two or more customers will								
exceed their limits?							d.	
Assume that the number of network errors experienced
in a day on a local area network (LAN) is distributed
as a Poisson random variable. The mean number of network
errors experienced in a day is 2.4. What is the probability
that in any given day

a. zero network errors will occur?
b. exactly one network error will occur?
c. two or more network errors will occur?
d. fewer than three network errors will occur?
The quality control manager of Marilyn’s
Cookies is inspecting a batch of chocolate-chip
cookies that has just been baked. If the production process is in
control, the mean number of chip parts per cookie is 6.0. What
is the probability that in any particular cookie being inspected

a. fewer than five chip parts will be found?
b. exactly five chip parts will be found?
c. five or more chip parts will be found?
d. either four or five chip parts will be found?