STAT EXAM 3

To do a z transformation, one must know only the mean and the value of the raw score to be transformed.

false

For a sample to be random, all the members must have an equal chance of being selected into the sample.

true

For any Z distribution of normally distributed scores, P50 or the 50th percentile is always equal to zero.

true

If an event is certain to occur, its probability of occurrence equals 1.00.

true

Probability values range from 0 to 1.

true

Sampling without replacement is usually used in choosing subjects for an independent groups design experiment.

true

The Addition Rule concerns one of at least two possible events.

true

The Multiplication Rule concerns the joint or successive occurrence of two or more events.

true

The addition and multiplication rules can apply to any number of events.

true

The addition rule is concerned with determining the probability of A or B, while the multiplication rule is concerned with determining the probability A and B.

true

The area beyond a z score of -1.12 is the same as the area beyond a z score of 1.12 of the data are normally distributed. Group of answer choices

true

The area under the normal curve represents the percentage of scores contained within the area

true

The normal curve never touches the X axis. Group of answer choices

true

The standard deviation of the Z distribution is always equal to 1.0

true

There is no division rule for probability.

true

Two events are independent if the occurrence of one has no effect on the probability of occurrence of the other.

true

When a variable is continuous, p(A) equals the area under the curve corresponding to A divided by the total area under the curve.

true

When events are mutually exclusive and exhaustive then the sum of the individual probabilities of each event in the set must equal 1.00.

true

Z scores allow comparison of variables that are measured on different scales

true

in a normal curve the area contained between the main and a score that is 1 standard deviation below the main is 0.34 of the total area

true

the Z distribution takes on the same shape as the raw scores

true

there is no division rule for probility

true

the normal curve is

unimodal

Would you rather have an income (assume a normal distribution and you are greedy) _________.

with a z score of 1.96

.

.

A Z score corresponding to the meaning of a raw score distribution equals

0

Given the following set of sample Ross scores X: 5, 10, 15. What is the Z transformed value for the raw score of 10

0

If A and B are mutually exclusive and exhaustive, then p(A and B) = _________.

0

The mean of the Z distribution equals

0

In a normal distribution the Z score for the mean equals

0 the z score for the median the z score for the mode all of there——— CORRECT ANSWER

Probabilities vary between _________.

0 and 1

A "hungry" undergraduate student was looking for a way of making some extra money. The student turned to a life of vice - gambling. To be a good gambler, he needed to know the probability of certain events. Help him out by answering the following question. A royal flush in poker is when you end up with the ace, king, queen, jack, and 10 of the same suit. It's the most rare event in poker. If you are playing with a well- shuffled, legitimate deck of 52 cards, what is the probability that if you are dealt 5 cards, you will have a royal flush? Assume randomness.

0.0000015

Let's assume you are having a party and have stocked your refrigerator with beverages. You have 12 bottles of Coors beer, 24 bottles of Rainier beer, 24 bottles of Schlitz light beer, 12 bottles of Hamms beer, 2 bottles of Heineken dark beer and 6 bottles of Pepsi soda. You go to the refrigerator to get beverages for your friends. In answering the following question assume you are randomly sampling without replacement. What is the probability your first three bottles selected are Pepsi's?

0.00024

A "hungry" undergraduate student was looking for a way of making some extra money. The student turned to a life of vice - gambling. To be a good gambler, he needed to know the probability of certain events. Help him out by answering the following question. The probability of drawing an ace, a king and a queen of any suit in that order is _________. Sampling is without replacement from a deck of 52 ordinary playing cards.

0.00048

The probability of drawing an ace followed by a king (without replacement) equals _________.

0.0060

If you have 15 red socks (individual, not pairs), 24 green socks, 17 blue socks, and 100 black socks, what is the probability you will reach in the drawer and randomly select a pair of green socks? (Assume sampling without replacement.)

0.0228

The probability of throwing two ones with a pair of dice equals _________.

0.0278

A "hungry" undergraduate student was looking for a way of making some extra money. The student turned to a life of vice - gambling. To be a good gambler, he needed to know the probability of certain events. Help him out by answering the following question. The probability of rolling "boxcars" (two sixes) with one roll of a pair of fair dice is _________.

0.028

Suppose you are going to randomly order individuals A, B, C, D, E and F. The probability the order will begin A B _ _ _ _ is _________.

0.033

If a town of 7000 people has 4000 females in it, then the probability of randomly selecting 6 females in six draws (with replacement) equals _________.

0.0348

A testing bureau reports that the mean for the population of Graduate Record Exam (GRE) scores is 500 with a standard deviation of 90. The scores are normally distributed.The proportion of scores that lie above 650 is _________.

0.0475

Assume you are rolling two fair dice once. The probability of obtaining a sum of 2 or 12 equals _________.

0.0556

A certain university maintains a colony of male mice for research purposes. The ages of the mice are normally distributed with a mean of 60 days and a standard deviation of 5.2. Assume you randomly sample one mouse from the colony. The probability his age will be greater than 68 is _________.

0.0618

The probability of correctly calling 4 tosses of an unbiased (fair or balanced) coin in a row equals _________.

0.0625

Assume you are rolling two fair dice once. The probability of obtaining a sum of 5 equals _________.

0.1111

A testing bureau reports that the mean for the population of graduate record exam scores is 500 with a standard deviation of 90 these scores are normally distributed the proportion of scores between 300 and 400 is

0.1203

Let's assume you are having a party and have stocked your refrigerator with beverages. You have 12 bottles of Coors beer, 24 bottles of Rainier beer, 24 bottles of Schlitz light beer, 12 bottles of Hamms beer, 2 bottles of Heineken dark beer and 6 bottles of Pepsi soda. You go to the refrigerator to get beverages for your friends. In answering the following question assume you are randomly sampling without replacement. What is the probability the first bottle selected is a Coors beer?

0.1500

The probability of randomly selecting a face card (K, Q, or J) or a spade in one draw equals _________

0.4231

Assume you are rolling two fair dice once. The probability of obtaining at least one 3 or one 4 equals _________.

0.5556

If a stranger gives you a coin and you toss it 1,000,000 times and it lands on heads 600,000 times, what is p(Heads) for that coin?

0.6000

If M = 35.2 and SD = 10, then p(X) for X is 39 or less equals _________. Assume random sampling and a normal distribution.

0.6480

The probability of rolling an even number or a one on a throw of a single die equals _________.

0.6667

A famous hypnotist performs in Meany Hall before a crowd of 350 students and 180 non-students. The hypnotist knows from previous experience that one-half of the students and two-thirds of the non-students are hypnotizable. What is the probability that a randomly chosen person from the audience will be hypnotizable or will be a non-student?

0.670

A certain university maintains a colony of male mice for research purposes. The ages of the mice are normally distributed with a mean of 60 days and a standard deviation of 5.2. Assume you randomly sample one mouse from the colony. The probability his age will be between 55 and 70 days is _________.

0.8041

Let's assume you are having a party and have stocked your refrigerator with beverages. You have 12 bottles of Coors beer, 24 bottles of Rainier beer, 24 bottles of Schlitz light beer, 12 bottles of Hamms beer, 2 bottles of Heineken dark beer and 6 bottles of Pepsi soda. You go to the refrigerator to get beverages for your friends. In answering the following question assume you are randomly sampling without replacement. What is the probability the first beverage you get is a beer?

0.9250

Given the following set of sample raw scores X: 5, 10, 15 what is the Z transformed value for the raw score of 15

1

Given the following set of sample raw scores, X: 5, 10, 15. What is the z transformed value for the raw score of 15?

1

The standard deviation of the Z distribution equals

1

A standardized test has a mean of 88 and a standard deviation of 12. What is the score at the 90th percentile? Assume a normal distribution.

103.36

On a test with a population mean of 75 and standard deviation equal to 16, if the scores are normally distributed, what is the percentile rank of a score of 56

11.70

A stockbroker has kept a daily record of the value of a particular stock over the years and finds that prices of the stock form a normal distribution with a mean of $8.52 with a standard deviation of $2.38 the percentage of scores that lie between $9 and $10 is

15.31%

On a test with a population mean of 75 and a standard deviation equal to 16 if the scores are normally distributed what percentage of scores fall between 70 and 80

24.34

Assuming the z scores are normally distributed, what is the percentile rank of a z score of -0.47?

31.92

A stockbroker has kept a daily record of the value of a particular stock over the years and find the prices of the stock form a normal distribution with a mean of $8.52 with a standard deviation of $2.38 what percentage of the distribution lies below $7.42

32.28%

A distribution has a mean of 60.0 and a standard deviation of 4.3 the raw score corresponding to a Z score of -1.5 is

53.5

If a population of scores is normally distributed, has a mean of 45 and a standard deviation of 6, the most extreme 5% of the scores lie beyond the score(s) of _________.

57 and 33

A distribution has a mean of 60.0 and a standard deviation of 4.3. The raw score corresponding to a z score of 0.00 is _________.

60.0

In a normal distribution approximately __________ of the scores will fall within one standard deviation of the mean

68%

A distribution has a mean of 60.0 in a standard deviation of four. Three the Raw score corresponding to a Z score of 2.02 is

68.7

On a test with a population mean of 75 and standard deviation equal to 16, if the scores are normally distributed, what percentage of scores fall below a score of 83.8?

70.88

A stockbroker has kept a daily record of the value of a particular stock over the years and finds that prices of the stock form a normal distribution with a mean of $8.52 with a standard deviation of $2.38.What percentage of the distribution lies between $5 and $11?

78.41%

In a normal distribution approximately _________ of the scores will fall within 2 standard deviation of the mean.

95%

A testing bureau reports that the mean for the population of Graduate Record Exam (GRE) scores is 500 with a standard deviation of 90. The scores are normally distributed.The percentile rank of a score of 667 is _________. Group of answer choices

96.86

A stockbroker has kept a daily record of the value of a particular stock over the years and finds that prices of the stock form a normal distribution with a mean of $8.52 with a standard deviation of $2.38.The percentile rank of a price of $13.87 is _________.

98.78%

A testing bureau reports that the mean for the population of Graduate Record Exam (GRE) scores is 500 with a standard deviation of 90. The scores are normally distributed.The proportion of scores that lie between 460 and 600 is _________.

99.73%

in a normal distribution approximately __________ of the scores will fall within three standard deviation of the mean

99.73%

The normal curve is

Bell shaped

the Z score corresponding to a raw score of 120 is

Impossible to compute from the information given

If p(A or B) = p(A) + p(B) then A and B must be _________.

Mutually Exclusive

If events A and B are independent, _________.

a previous event does not influence a subsequent event

All bell-shaped curves _________.

are symmetrical

A testing service has 1000 raw scores. It wants to transform the distribution so that the mean = 10 and the standard deviation = 1. To do so, _________.

do a z transformation for each raw score and add 10 to each z score

A z score and the z distribution are the same thing.

fALSE

A Z distribution always is normally shaped

false

A biased sample results when each possible sample of a given size has an equal chance of being selected.

false

Events that occur only rarely have a probability equal to 0.00.

false

For all problems, we must use either the Addition Rule or the Multiplication Rule, but not both.

false

If A and B are independent then p(B|A) = p(A) or p(B).

false

If sampling is without replacement, the events are independent.

false

If the original raw score distribution has a mean that is not equal to zero, the mean of the z transformed scores will not equal zero either.

false

If the raw score distribution is very positively skewed the standard deviation of the Z transformed scores will not equal one

false

If the raw score distribution is very positively skewed, the standard deviation of the z transformed scores will not equal 1.

false

In a normal curve, the area contained between the mean and a score that is 2 standard deviation above the mean is 0.34 of the total area.

false

In a plot of the normal curve frequency is plotted on the X axis

false

It is impossible to have a z score of 30.2.

false

One cannot reasonably do z transformations on ratio data.

false

Percent values range from 0 to 1.

false

Probability values range from -1.00 to +1.00.

false

The Addition Rule concerns the joint or successive occurrence of two or more events.

false

The Multiplication Rule concerns one of at least two possible events.

false

Two events are considered mutually exclusive if the probability of one event does not influence the probability of a second event.

false

When a sampled score is put back in the population before selecting the next score, this process is called sampling without replacement.

false

When two events are mutually exclusive then p(A and B) must equal 1.00.

false

if the original Raw score distribution is not normally distributed the mean of the Z transformation scores of the raw data will not equal zero

false

in the standard normal curve 14% of the scores will always be contained between the mean and +1s

false

percent values range from 0 to 1

false

AZ score is a raw score

fase

The normal curve is _________.

found commonly in nature

If p(A or B) = p(A) + p(B) then A and B must be _________.

mutually exclusive

If a distribution of raw scores is negatively skewed, transforming the raw scores into z scores will result in a _________ distribution.

negativeky skewed

Makaela took a Spanish exam; her grade was 79. The distribution was normally shaped with M= 70 and SD = 12. Juan took a History exam; his grade was 86. The distribution was normally shaped with M= 80 and SD = 8. Which did better on their exam relative to those taking the exam?

neither, they both did as well as each other

The Multiplication Rule states _________.

p(A and B) = p(A)p(B|A)

The Addition Rule states _________.

p(A or B) = p(A) + p(B) - p(A and B)

If the probability of drawing a member of a population is equal for all members, then the sample is said to be _________.

random

A set of raw scores has a rectangular shape the Z transformed scores for this set of raw scores has a _________ shape

rectangular

A set of raw scores has a rectangular shape. The Z transformed scores for this set of raw scores has a___________ shape

rectangular

you have just taken a standardized skills test design to help you make a career choice. Your math skills score was 63 and your writing skills score was 45. The standard math distribution is normally distributed with M=50 and SD=8. The writing skills score distribution is also normally distributed with M=30 and SD=10 based on this information as between pursuing a career that requires good math skills or one requiring good writing skills you should choose

the career requiring good math skills

you have just taken a standardized skills test designed to help you make a career choice. Your science skills score was 60 and your writing skills score was 45. The standardized science distribution is normally distributed, with M = 50, and SD = 8. The writing skills score distribution is also normally distributed, with M = 30, and SD = 10. Based on this information, as between pursuing a career that requires good math skills or one requiring good writing skills, you should chose _________.

the career requiring good writing skills

Two events are dependent if _________.

the occurrence of one alters the probability of occurrence of the other

Two events are independent if _________.

the occurrence of one has no effect on the probability of occurrence of the other

Two events are mutually exclusive if _________.

they both cannot occur together

A Z score is a standard score

true

A random sample results when each possible sample of a given size has an equal chance of being selected.

true

A z score designates how many standard deviations the raw score is above or below the mean.

true

A z score is a transformed score.

true

AZ transformation will allow comparisons to be made when units of distributions are different

true