A dataset contains the ages of students in a class: 18, 19, 18, 20, 21, 18. What is the mode of this dataset?
21
18
19
20
The mean of a dataset is 15 and the standard deviation is 3. What percentage of data points lie within 12 and 18?
Approximately 95%
Approximately 99.7%
Cannot be determined from the given information
Approximately 68%
Which of the following is NOT affected by outliers?
Median
Standard Deviation
Mean
Range
What does a variance of zero indicate about a dataset?
The data is perfectly normally distributed.
All data points are the same.
The dataset has a large amount of variation.
The mean is zero.
In a probability distribution, what does a higher peak indicate?
Lower probability of values around the peak
Smaller sample size
Greater variability in the data
Higher probability of values around the peak
What type of chart is best for displaying the distribution of a single continuous variable?
Bar Chart
Histogram
Pie Chart
Scatter Plot
The area under a probability distribution curve represents:
The mean of the distribution
The standard deviation of the distribution
The probability of a specific value occurring
The total probability of all possible outcomes, which always equals 1
What does the significance level (alpha) represent in hypothesis testing?
The probability of making a Type II error.
The probability of obtaining the observed data.
The strength of the relationship between variables.
The threshold below which we reject the null hypothesis.
Descriptive statistics primarily deals with:
Drawing conclusions about populations from samples
Summarizing and visualizing existing data
Predicting future outcomes based on data trends
Testing hypotheses about population parameters
Which of the following is NOT a type of discrete probability distribution?
Bernoulli distribution
Binomial distribution
Normal distribution
Poisson distribution