QTM 100 Exam 1 Graded A+
____ is not resistant to outliers, ______ is. (2) - ANSWER-1. mean (range, and
standard deviation)
2. median (IQR)
5-number summary of data (5) - ANSWER-1. minimum value
2. Q1
3. median
4. Q3
5. maximum value
A and B are independent events if either of these rules is satisfied: - ANSWER-1. P(A
and B)/P(B)= P(A)
2. P(A and B)= P(A) x P(B)
an event is unusual if it has a probability less than____ - ANSWER-.05
association - ANSWER-if there is a relationship between response and explanatory
bell-shaped - ANSWER-data follows a bell shaped curve
bimodal - ANSWER-has two peaks
Binomial distribution - ANSWER-X ~ Bin(n,p)
blinding - ANSWER-experimental units do not know which group they are in
block - ANSWER-account for variables known or suspected to affect the response of
interest
Calculate outliers (2) - ANSWER-1. falls below Q1- 1.5 x IQR
2. is above Q3+ 1.5 x IQR
categorical (2) - ANSWER-(descriptive)
1. dichotomous- two categories
2. ordinal- natural ordering
categorical vs. categorical - ANSWER-2x2 contingency table, barplot
census - ANSWER-collecting data on everyone
Central limit theorem - ANSWER-regardless of the shape of the underlying population
distribution, as the sample size n increases, the sampling distribution of the sample
mean approaches an approx. normal distribution (n >30).
, cluster random sampling - ANSWER-naturally occurring groups
Complement Rule - ANSWER-P(A^c)= 1 - P(A)
conditional probability - ANSWER-based on two (or more) variables, but is isolated on a
level of one of those variables (within a single row/column of the table)
conditions for binomial distribution (4) - ANSWER-1.trials are independent
2. the number of trials (n) is fixed
3. each trial has two possible outcomes: "success" vs. "failure"
4. each trial has the same probability of success p
conditions that must be met to have a normal distribution of sample proportion -
ANSWER-1. np>10
2. n(1-p)>10
Conditions to apply the empirical rule (3) - ANSWER-1. unimodal
2. (approx.) symmetric
3. bell-shaped
confounding variable - ANSWER-occurs when a third variable is associated with both
the explanatory and response variable
control group - ANSWER-compare treatment of interest to this group
data distribution - ANSWER-refers to the distribution of observed values from a sample
descriptive statistics - ANSWER-used to summarize the collected data through numbers
such as averages and percentages
disjoint - ANSWER-when events do not have any common outcomes
double-blind - ANSWER-both experimental units and the experimenter do not know the
group assignment
dsitribution - ANSWER-tells the possible values the variable as well as the occurrence
of those values
Empirical rule (3) - ANSWER-1. 68% of observations fall within 1 standard deviation of
the mean
2. 95% of observations fall within 2
3. nearly 100% fall within 3 (if not potential outliers)
event - ANSWER-the subset of the sample space
____ is not resistant to outliers, ______ is. (2) - ANSWER-1. mean (range, and
standard deviation)
2. median (IQR)
5-number summary of data (5) - ANSWER-1. minimum value
2. Q1
3. median
4. Q3
5. maximum value
A and B are independent events if either of these rules is satisfied: - ANSWER-1. P(A
and B)/P(B)= P(A)
2. P(A and B)= P(A) x P(B)
an event is unusual if it has a probability less than____ - ANSWER-.05
association - ANSWER-if there is a relationship between response and explanatory
bell-shaped - ANSWER-data follows a bell shaped curve
bimodal - ANSWER-has two peaks
Binomial distribution - ANSWER-X ~ Bin(n,p)
blinding - ANSWER-experimental units do not know which group they are in
block - ANSWER-account for variables known or suspected to affect the response of
interest
Calculate outliers (2) - ANSWER-1. falls below Q1- 1.5 x IQR
2. is above Q3+ 1.5 x IQR
categorical (2) - ANSWER-(descriptive)
1. dichotomous- two categories
2. ordinal- natural ordering
categorical vs. categorical - ANSWER-2x2 contingency table, barplot
census - ANSWER-collecting data on everyone
Central limit theorem - ANSWER-regardless of the shape of the underlying population
distribution, as the sample size n increases, the sampling distribution of the sample
mean approaches an approx. normal distribution (n >30).
, cluster random sampling - ANSWER-naturally occurring groups
Complement Rule - ANSWER-P(A^c)= 1 - P(A)
conditional probability - ANSWER-based on two (or more) variables, but is isolated on a
level of one of those variables (within a single row/column of the table)
conditions for binomial distribution (4) - ANSWER-1.trials are independent
2. the number of trials (n) is fixed
3. each trial has two possible outcomes: "success" vs. "failure"
4. each trial has the same probability of success p
conditions that must be met to have a normal distribution of sample proportion -
ANSWER-1. np>10
2. n(1-p)>10
Conditions to apply the empirical rule (3) - ANSWER-1. unimodal
2. (approx.) symmetric
3. bell-shaped
confounding variable - ANSWER-occurs when a third variable is associated with both
the explanatory and response variable
control group - ANSWER-compare treatment of interest to this group
data distribution - ANSWER-refers to the distribution of observed values from a sample
descriptive statistics - ANSWER-used to summarize the collected data through numbers
such as averages and percentages
disjoint - ANSWER-when events do not have any common outcomes
double-blind - ANSWER-both experimental units and the experimenter do not know the
group assignment
dsitribution - ANSWER-tells the possible values the variable as well as the occurrence
of those values
Empirical rule (3) - ANSWER-1. 68% of observations fall within 1 standard deviation of
the mean
2. 95% of observations fall within 2
3. nearly 100% fall within 3 (if not potential outliers)
event - ANSWER-the subset of the sample space
