What does the significance level (alpha) represent in hypothesis testing?
The probability of obtaining the observed data.
The probability of making a Type II error.
The strength of the relationship between variables.
The threshold below which we reject the null hypothesis.
What does the alternative hypothesis typically represent?
The statement that is always rejected in hypothesis testing.
The statement that is always accepted in hypothesis testing.
The statement of no effect or no difference.
The opposite of the null hypothesis.
The mean of a dataset is 15 and the standard deviation is 3. What percentage of data points lie within 12 and 18?
Cannot be determined from the given information
Approximately 68%
Approximately 99.7%
Approximately 95%
Which of the following is an example of a variable measured at the interval level?
Letter Grade (A, B, C, D, F)
Temperature in Fahrenheit
Height in centimeters
Gender
What level of measurement is represented by the ranking of restaurants from 1 to 5 stars?
Interval
Ratio
Ordinal
Nominal
What is the range of the following dataset: 7, 12, 4, 9, 15, 11?
4
15
8
11
A researcher wants to survey a sample of students from a university. They randomly select 5 departments and then survey every student within those departments. What sampling method is being used?
Stratified Sampling
Simple Random Sampling
Systematic Sampling
Cluster Sampling
Which type of chart is particularly useful for comparing the distribution of a variable across different categories?
Pie Chart
Box Plot
Scatter Plot
Histogram
The 25th percentile is also known as the:
Interquartile Range
Third Quartile
Second Quartile
First Quartile
If the p-value is less than the significance level, what decision do we make regarding the null hypothesis?
Fail to reject the null hypothesis.
Reject the null hypothesis.
Conclude that the null hypothesis is true.
Accept the null hypothesis.