Mid-term exam (unit 1-3)

Question 1

What is a Venn diagram?

Answer 1

It’s a box like diagram with all possible outcomes of an experiment

Question 1

What is an Experiment?

Answer 1

a process that results in one (only) of many observations

Question 2

What is an Outcome?

Answer 2

observations of the experiment

Question 3

What is a Sample space?

Answer 3

all the potential outcomes of the experiment

Question 4

What is a Simple event?

Answer 4

includes only one of the final outcomes

Question 5

What is a Compound events?

Answer 5

consist of more than one outcome (ex.: at most one man is selected - therefore multiple outcomes)

Question 6

What is a Population?

Answer 6

consists of all elements being studied in statistics

Question 7

What is a Sample?

Answer 7

A portion of the population selected for study

Question 8

What is a Representative Sample?

Answer 8

Sample that represents characteristics of the population

Question 9

What is a Random sample?

Answer 9

Random selection of the population so each element of the population has a chance of being selected

Question 10

What is a Sampling with replacement?

Answer 10

elements are put back into the population - therefore contains the same number of items each time a selection is made

Question 11

What is a Sampling without replacement?

Answer 11

not put back into the population

Question 12

What is a Census?

Answer 12

A survey that includes every member of the population

Question 13

What is a Quantitative variable?

Answer 13

a variable that can be measured numerically (ex.: incomes, height, number of houses)

Question 14

What is a Qualitative variable?

Answer 14

Non-numerical variable (ex.: gender, hair color)

Question 15

What is a Discrete variable?

Answer 15

Variable whose values are countable (ex.: 0, 1, 2, 3… but not in between intervals like in between 0 to 2)

Question 16

What is a Continuous variable?

Answer 16

Variable that aren’t countable and has a value over a certain interval (ex.: time, weight…between 30 and 60 minutes)

Question 17

What is a Frequency distribution for qualitative data?

Answer 17

Frequency distribution for qualitative data lists all categories and the number of elements that belong to each of the categories

Question 18

How do you calculate midpoint of a class?

Answer 18

(upper limit + lower limit)/2

Question 19

What is a Frequency distribution for quantitative data?

Answer 19

Frequency distribution for quantitative data lists all the classes and the number of values that belong to each class. It is called grouped data.

Question 20

What is a Class boundery?

Answer 20

is the midpoint of the upper limit and the lower limit of the next class. (ex.: Class limits 401 to 600 would be 400.5 to less than 600.5)

Question 21

How do you calculate class width?

Answer 21

(Largest value - Smallest value)/number of class

Question 22

What is a Right Skewed histogram?

Answer 22

The curve is longer on the right of the histogram

Question 23

What is a Left Skewed histogram?

Answer 23

The curve is longer on the left of the histogram

Question 24

What are Outliers?

Answer 24

Values that are very small or very large relative to the majority of the values

Question 25

What is a Mode?

Answer 25

Value that occurs with the highest frequency in a data set.

Question 26

What are Quartiles?

Answer 26

are three summary measures that divide a ranked data set into four equal parts.

Question 27

What are the two properties of probability?

Answer 27

1. Probability of an event always lies in the range of 0 to 1 & 2. The sum of all probabilities of all simple events always equals 1.

Question 28

What means Equally likely outcomes?

Answer 28

Various outcomes who have the same probability of occurence.

Question 29

What is the relative frequency probability?

Answer 29

the approximation for the probability of an event.

Question 30

What is a Subjective probability?

Answer 30

probability assigned to an event based on subjective judgment, experience, information and belief.

Question 31

What is a marginal probability?

Answer 31

is the probability of a single event without consideration for other event. Also called simple probability.

Question 32

What is a conditional probability?

Answer 32

is the probability of an event to occur given that another event has already occurred. If A and B are two events, the probability of A given B is…. P(A | B)

Question 33

What are mutually exclusive events?

Answer 33

events that cannot occur together.

Question 34

What are independent events?

Answer 34

two events are said to be independent if one doesn’t affect the occurrence of the other. For example: A and B are independent events if… Either P(A | B) = P(A) or P(B | A) = P(B)

Question 35

What are complementary events?

Answer 35

the complement of A, denoted by A (with a bar on top) and read as “A bar” or “A complement” is the event that includes all the outcomes for an experiment that are not in A.

Question 36

What is the intersection of events?

Answer 36

is given by the outcomes that are common to both events. It is denoted by A and B or AB or A  B (reverse U in between).

Question 37

What are joint probabilities?

Answer 37

probability of the intersection of two events.

Question 38

What are the union of events?

Answer 38

is the collection of all outcomes that belong either to A or to B or to both A and B and is denoted by… A or B

Question 39

What are random variables?

Answer 39

is a variable whose value is determined by the outcome of a random experiment. Usually random variable is denoted by X or Y

Question 40

What are discrete random variables?

Answer 40

a variable that has countable values (ex.: number of cars, houses or electronics sold)

Question 41

What are continuous random variable?

Answer 41

a variable that has a value obtained from one or more intervals. (ex.: height of a person, weight of a fish, time to complete an exam)

Question 42

What is the probability distribution of a discrete random variable?

Answer 42

list all the possible values a random variable can have and their corresponding probabilities.

Question 43

What is factorial?

Answer 43

the symbol n! read as “n factorial” represents the product of all integers from n to 1 (ex.: 7! = 7 * 6 * 5 * 4 * 3 * 2 * 1 = 5040)

Question 44

What is a combination?

Answer 44

give the number of ways X elements can be selected from n elements. And is denoted by…nCx.(ex.: 5 cards draw from a 52 cards deck - 52C5)

Question 45

What are the conditions of a binomial experiment?

Answer 45

A binomial experiment needs to satisfy the following 4 conditions: 1- There are n identical trials. 2- Each trial has only two possible outcomes. 3- The probabilities of the two outcomes remain constant. 4- The trials are independent.

Question 46

When do we use standard normal distribution?

Answer 46

We use standard normal distribution table when the values of np & nq is greater than 5. So when… np > 5 and nq > 5

Question 47

What is the continuity correction factor and when is it applied?

Answer 47

is the addition of 0.5 and/or subtraction of 0.5 from the value(s) of x when the normal distribution is used as an approximation to the binomial distribution.

Question 48

What is the concept of Z values?

Answer 48

The Z values are the horizontal axis on a curve, and determine a position on the curve. The Z value for the mean is always 0.