StraighterLine Statistics Quiz Practice
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales
2025|2026 Q&A | Instant Download Pdf
1. What type of data consists of categories without any order?
A. Ordinal
B. Interval
C. Ratio
D. Nominal
Nominal data represents categories with no inherent order, like
gender or colors.
2. Which measure of central tendency is most affected by outliers?
A. Median
B. Mode
C. Mean
D. Range
, The mean is sensitive to extremely high or low values because it
incorporates all data points.
3. In a normal distribution, approximately what percent of data falls
within one standard deviation of the mean?
A. 50%
B. 68%
C. 95%
D. 99%
According to the empirical rule, about 68% of values lie within ±1
standard deviation in a normal distribution.
4. A study reports a correlation coefficient of -0.85. This indicates:
A. A weak positive relationship
B. No relationship
C. A weak negative relationship
D. A strong negative relationship
Correlation values close to -1 indicate a strong negative relationship
between variables.
5. If the probability of an event occurring is 0.2, the probability of it not
occurring is:
A. 0.1
B. 0.2
C. 0.8
, D. 0.9
The probabilities must sum to 1, so 1 - 0.2 = 0.8.
6. What is the shape of a distribution with a long tail on the right?
A. Symmetrical
B. Left-skewed
C. Right-skewed
D. Uniform
A right-skewed distribution has most data on the left and a tail
stretching to the right.
7. Which measure of dispersion is the square root of the variance?
A. Range
B. Mean absolute deviation
C. Standard deviation
D. Interquartile range
Standard deviation is the square root of variance, representing the
average deviation from the mean.
8. Which sampling method ensures every member has an equal chance
of selection?
A. Simple random sampling
B. Convenience sampling
C. Stratified sampling
D. Cluster sampling
, Simple random sampling gives all individuals in the population an
equal chance of being chosen.
9. What is the median of the data set: 3, 7, 8, 12, 15?
A. 7
B. 8
C. 10
D. 12
Median is the middle value when data are ordered; here, the third
value is 8.
10. In hypothesis testing, the null hypothesis represents:
A. No effect or difference
B. The research question
C. A significant effect
D. The alternative outcome
The null hypothesis assumes no effect or difference in the population.
11. A z-score indicates:
A. The probability of an event
B. The mean of the dataset
C. The number of standard deviations a value is from the mean
D. The variance
Z-scores standardize data to show how far a value is from the mean
in standard deviation units.
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales
2025|2026 Q&A | Instant Download Pdf
1. What type of data consists of categories without any order?
A. Ordinal
B. Interval
C. Ratio
D. Nominal
Nominal data represents categories with no inherent order, like
gender or colors.
2. Which measure of central tendency is most affected by outliers?
A. Median
B. Mode
C. Mean
D. Range
, The mean is sensitive to extremely high or low values because it
incorporates all data points.
3. In a normal distribution, approximately what percent of data falls
within one standard deviation of the mean?
A. 50%
B. 68%
C. 95%
D. 99%
According to the empirical rule, about 68% of values lie within ±1
standard deviation in a normal distribution.
4. A study reports a correlation coefficient of -0.85. This indicates:
A. A weak positive relationship
B. No relationship
C. A weak negative relationship
D. A strong negative relationship
Correlation values close to -1 indicate a strong negative relationship
between variables.
5. If the probability of an event occurring is 0.2, the probability of it not
occurring is:
A. 0.1
B. 0.2
C. 0.8
, D. 0.9
The probabilities must sum to 1, so 1 - 0.2 = 0.8.
6. What is the shape of a distribution with a long tail on the right?
A. Symmetrical
B. Left-skewed
C. Right-skewed
D. Uniform
A right-skewed distribution has most data on the left and a tail
stretching to the right.
7. Which measure of dispersion is the square root of the variance?
A. Range
B. Mean absolute deviation
C. Standard deviation
D. Interquartile range
Standard deviation is the square root of variance, representing the
average deviation from the mean.
8. Which sampling method ensures every member has an equal chance
of selection?
A. Simple random sampling
B. Convenience sampling
C. Stratified sampling
D. Cluster sampling
, Simple random sampling gives all individuals in the population an
equal chance of being chosen.
9. What is the median of the data set: 3, 7, 8, 12, 15?
A. 7
B. 8
C. 10
D. 12
Median is the middle value when data are ordered; here, the third
value is 8.
10. In hypothesis testing, the null hypothesis represents:
A. No effect or difference
B. The research question
C. A significant effect
D. The alternative outcome
The null hypothesis assumes no effect or difference in the population.
11. A z-score indicates:
A. The probability of an event
B. The mean of the dataset
C. The number of standard deviations a value is from the mean
D. The variance
Z-scores standardize data to show how far a value is from the mean
in standard deviation units.
