1-A Fair Coin Is to Be Flipped 4 Times. the First 3 Flips Land Heads Up. What Is the Probability

1-A fair coin is to be flipped 4 times. The first 3 flips land heads up. What is the probability that the next flip will land heads up?

Select one:

0.0625

0.25

0.5

2-Suppose that the heights of adult women are normally distributed with mean 65 inches and standard deviation 2 inches.
Which of the following is closest to the correct percentile for a woman with height 64 inches?

80th

60th

20th

50th

70th

40th

30th

If Rachael is at the 99th percentile in height for adult women, then which of the following is closest to her height?

70 inches

74 inches

68 inches

62 inches

60 inches

3-Suppose you are an electrician trying to find a short in a 4 meter length of wire. Assume that the short is equally likely to be found at any point in the wire (i.e. uniform distribution). What is the probability you find the short in the last half-meter of the wire?

Select one:

0.125

0.25

0.375

0.5

4-A company manufactures its circuit boards by selecting 4 computer chips at random from a large batch of chips. Suppose that in this batch, 90% of the chips are acceptable. Let X represent the number of acceptable chips out of a sample of 4 chips from this batch.
The distribution of X is binomial. Explain why.

Answer:

5-Using the same random variable X from the previous question, find the values of n and p.
n =Answer
p =Answer
Which of the following is the LEAST likely value of X?

6-In a population of a certain kind of shellfish, the lengths of individual shellfish are approximately normally distributed. The mean length is 10 centimeters and the standard deviation is 0.2 centimeters.
If we have 10,000 of this type of shellfish, about how many have length between 9.5 and 10.5 centimeters?

9,735

9,500

9,970

6,800

9,876

If we have 10,000 of this type of shellfish, which of the following is the narrowest interval that will include about 4,000 shellfish?

9.895 cm to 10.105 cm

9.298 cm to 10.080 cm

9.744 cm to 10.256 cm

9.744 cm to 10 cm

0 cm to 9.949 cm

7-Suppose that a tax increase is being proposed for a large city in order to support the public school system. Further suppose that 55% of the city’s population is in favor of the tax, and 45% of the population is against the tax. If a random sample of 400 people from this city are interviewed, what is the probability that 200 or fewer people in the sample will support the tax increase?
Hint: Use the binomial distribution to calculate this probability.

Select one:

0.0252

0.0909

0.5

0.55

0.9091

0.9801

For continuous random variables we CANNOT find probabilites for exact outcomes.

Select one:

True

False

If the probability of event A is .78, then the probability of the complement of event A is .22.

Select one:

True

False

The sum of all probabilities for all events which complete a sample space must equal 0.

Select one:

True

False

A probability is: the porportion of times a specific outcome would occur over the long run.

Select one:

True

False

The conditional probability, P(A|B) means event B occurs given that event A occurs first.

Select one:

True

False

A study of 100 people, 50 men and 50 women, found 40 of those people prefer a dog as their pet of choice. Thirty (30) of the 40 people who prefer a dog as their pet were men.

The probabilities are fractions and the denominators are NOT reduced: Example: P(man) = 50/100

The events of selecting a man and a woman / · Drag answer here
P(man|prefer a dog) = / · Drag answer here
Complement of P(man and a dog is his preferred pet) = / · Drag answer here
P(prefer a dog|man) = / · Drag answer here
P(woman) / · Drag answer here
P(man|woman) = / · Drag answer here
The P(prefer dog) = / · Drag answer here
P(prefer a cat) = / · Drag answer here
P(woman|prefer a dog) = / · Drag answer here
P(not prefer a dog) = / · Drag answer here

· not defined in this study

· 80/100

· 40/100

· 50/50

· 30/50

· 10/40

· 0/50 or zero

· 60/100

· 30/40

· are mutually exclusive

· 70/100

· 50/100

Jake said, "I think there is a 50% chance of rain today"

This is an example of a personal probability.

Select one:

True

False

Sally is going to play a simple game. There are 10 blocks in a box, 5 red = R, 3 yellow = Y and 2 blue = B.

Sally without looking will randomly pick a block; if the block is red she flips a coin, heads (H) sheWINS tails (T) she loses. If she picks a yellow block she automatically loses. If she picks a blue block she automatically wins.

o Answer the following questions about the sample space and probabilities of the game.

o A good organized approach is to use the example of the tree diagram on Pages 241 and 242.

P(Y) = / · Drag answer here
P(WINNING his game ) = / · Drag answer here
P(R then H) = / · Drag answer here
P(R or Y) = / · Drag answer here
P ( losing this game) = / · Drag answer here
The probability of R and B / · Drag answer here
The sample space is modeled by: / · Drag answer here

· 8/10

· 3/10

· RH RT YH YT BH BT

· 5/20 + 2/10 = 9/20

· R Y B H T

· 7/10 + 1/20 = 15/20

· 3/10 + 2/20 = 8/20

· 5/20 + 3/10 = 11/20

· 5/20 = 1/4

· RH RT Y B

· are mutually exclusive