# Statement 6587

Question #12
The principle of redundancy is used when system reliability is improved through redundant or backup components. Assume that a students alarm clock has a 15.1% daily failure rate.
A. What is the probability that the student’s alarm clock will not work on the morning of an important final exam? ____ (Round to three).

b. I the student has two such alarm clocks, what is the probability that they both fail on the morning of an important final exam? ____ Round to five.

c- What is the probability of not being awakened if the student uses three independent alarm clocks? _____ Round to five places.

D. Do the second and third alarm clocks result in greatly improved reliability?
a. Yes, because total malfunction would not be impossible, but it would be unlikely.
b. No, because the malfunction of both is equally or more likely than the malfunctions of one.
c. Yes, because you can always be certain that at least one alarm clock will work.
d- No, because total malfunction would still not be unlikely.

Question #13 –
The date represents the results for a test for a certain disease. Assume one individual form the group is randomly selected, Find the probability of getting someone who test positive, given that he or she had the disease.
Data: Top has The individual actually had the disease
Postive Yes – 132 and no 23
Negative – 19 and 126
The probability is approx. ____ (Round to three )

Question #14 –
Column has two data points: Positive Test Results (Pregnancy is indicated) and Negative Test Results (Pregnancy is not indicated).
Data:
Subject is Pregnant : 62 and 7
Subject in not pregnant: 2 and 28
P(Pregnant) = _____

A test subject is randomly selected and is given a pregnancy test. What is the probability of getting a subject who is pregnant.
P(Pregnant /Positive = ____

Question #15
Determine whether the following value is a continuous random variable, discrete random variable, or not a random variable.
a. the # of runs scored during a game.
b. usual mode of transportation of people in city a.
c. the number of hits to a website in a week.
d. the distance of football travels in the air.
e. the amount of rainfall in a country in a year.
f. the # of text book authors now eating a meal.
A . Is the number of runs scored during a baseball game a discrete random variable, continuous random variable, or not a randome variable?
a. It is a discrete random variable.
b. it is a continuous random variable.
c. it is not a randome variable.

b. Is the usual mode of transportation of people in city A discrete random variable, continuous random variable, or not a random variable?
a. It is a discrete random variable.
b. It is a continuous random variable.
c. It is not a random variable.

C. Is the number of hits to a website in a week a discrete random variable, or not a random variable?
a. It is a continous random variable.
b. it is a discrete random variable.
c. It is not a random variable.

E. Is the amount of rainfall in a country in a year a discrete random variable, continuous random variable, or not a random variable?
a. It is a discrete random variable.
b. it is a continous random variable.
c. it is not a random variable.

F. Is the number of textbooks authors now eating a meal a discrete random variable, continuous random variable, or not a random variable?
a. If is a discrete random variable.
b. it is a continuous random variable.
c. it is not a random variable.

Question #16-
Pea question X being # of offspring with green pods.
Data: Probabiltity of Number of Peas with Green Pods among 8 offspring
Two colums
X and P(x)
0 0+
1 0+
2 0.002
3 0.019
4 0.087
5 0.205
6 0.316
7 0.263
8 0.108
a – Find the probability of getting exactly 7 peas with green pods.
____

b. Find the probability of getting 7 or more peas with green pods.
______

C. Which probability is relevant for determining wheather 7 is an unusually high # with green pods, the results from part (a) and (b)?
__ The result of part (b)
__ the result from part (a)

d. Is 7 unusually high # of peas green pods? Why or why not? Use 0.05
a Yes, < 0.05 is unusuall high number b. No > 0.05 not a unusually high #
c. no, since ~ < 0.05 is not an unsually high #
d. Yes, since ~ Greater 0.05 is an unusually high number.

Question #17
Assume that a procedure yields a binomial distribution with a trail repeated n times,
n = 7, X= 3, p = 0.75
p( 3) = ____ Round to three

Question #18
A brand name has a 40 % recognition rate. Assume owners wants rate of small sample of 5 random customers.
What is probability that exactly 4 of the selected cosuomers recognize the brand?
The probabilty that exactly 4 of 5 consumers recoginaze the brand name ___ round to three

b. the probabilty that all of the selected consumers recognize the brand name is ___ round to three.
c. What is the probability that a least 4 of the consumers recognize the brand name ___ Round to three.

d. If 5 consumers are randomly are randomly selected is 4 and unusually high #
a. Yes, 4 is more than selected and < 0.05 b. Yes, 4 is more slected > 0.05
c. No, 4 is < 0.05 d. No, 4 is > 0.05

Question 19
Assume the binomal distrubuiton with n trials and the probability for one trial is P.
In an analysis of prelimialry rest results a gender selecton 24 babies are born and it is assumed 50% are girls and so n= 24 and p = 0.5
u = ____
Standard deviation o = ____ One decimal place
Min usual valve u – 2o = ___ Round to one.
Max usual valve u+2o = ____ round to one.

Q 24
A research polls on bad drivers n = 2392 and x = 1013 use 99%
a. Find best point est. population proportion p ____ round to three.

b. Margin of error E E = ____ round to 4

c. Construtethe confident interval.
___ < p < ___

d. Write the statement the correct interprets the confidence interval.
a. 99% that true value of population proportion will fail between the lower bound and upper bound.
b. one has 99% from lower bound to the upper bound actually does contain the true value of population proportion.
c. 99% of sample proportions will fail between the lower bound and the upper bound.
c. one has 99% confidence that the smaple proportion is equal ot the population proportion.