Question

Suppose in an asymmetric and continuous distribution P(X< -131) = P(-131<X< -57) = P(-57 < X< 29) = P(X>29). Which of the following is correct? A. mean=median=-131 B. mean=median= -57 C. median is -131, mean is unknown D. median is -57, mean is unknown E. median is -34, mean is unknown

In Questions 2-4 suppose there are a total of 15 Carbon Monoxide Detectors in a building and event “Y” is defined as Y={At least 9 of these detectors work}. Further suppose P(each detector work)=0.8, and detectors are independent of each other. Which of the following is the Ybar (complement of Y)? A. Ybar={At least 5 detectors fail} B. Ybar={At least 6 detectors fail} C. Ybar={At most 6 detectors fail} D. Ybar={At least 7 detectors fail} E. Ybar={At most 7 detectors fail}

What is the probability that detectors number 3, 4, 11, 15 fail and the other 11 detectors work? A. 0.8^4 * 0.2^11 * 15!/(4! * 11!) B. 0.8^4 * 0.2^11 C. 0.8^11 * 0.2^4 * 15!/(4! * 11!) D. 0.8^11 * 0.2^4

What is the probability that 11 detectors work and 4 detectors fail? (Hint: Here we don’t care which 4 to fail, just any 4). A. 0.8^4 * 0.2^11 * 15!/(4! * 11!) B. 0.8^4 * 0.2^11 C. 0.8^11 * 0.2^4 * 15!/(4! * 11!) D. 0.8^11 * 0.2^4

Answer 1

ANSWER:

A)

There re  4 square with zones are given so the qualities will compare to 25th, 50th and 75th percentile.

Consequently, 25th percentile = - 131

50th percentile = - 57

75th percentile = 29.

Since this circulation is skewed, we can't enlighten anything regarding mean from the given data.

Middle = 50th is percentile = - 57

Option D is correct answer

B)

Required data is

Total detector =15

Y={at lease 9 detectors work}

P(each detector work)=0.8 =?

Y complement is :

Y bar={At least 7 detectors fail}.

Option D is correct answer .

C)

Required data is given by

Detectors numbers are 3,4,11,15

We have to obtained probability is

P(Detectors 3,4,11,15 fails)= 0.8^11 * 0.2^4.

Option D is correct answer .

D)

Required information is given by

probability 11 detectors is work and 4 detectors are fail than

Here,

Probability is

=P(Any Four detector fails )

=(15 c 4) *(0.8) ^(11 )*(0.2)^(4).

Option is C correct answer .