#1
What is the formula for calculating the mean of a set of numbers?
Sum of numbers divided by the count of numbers
ExplanationAdd up all the numbers and divide by how many there are.
#2
In statistics, what does 'median' refer to?
The middle value when data is arranged in ascending order
ExplanationIt's the value at the center of a sorted list of numbers.
#3
What is the purpose of a histogram?
To display the distribution of continuous data
ExplanationIt shows the frequency distribution of continuous data.
#4
What is the formula for calculating the interquartile range (IQR)?
Third quartile minus first quartile
ExplanationIt measures the spread of middle 50% of the data.
#5
Which of the following is a measure of dispersion?
Standard deviation
ExplanationIt shows how spread out the numbers in a data set are.
#6
What is the formula for calculating standard deviation?
Square root of the variance
ExplanationIt's the square root of the average of the squared differences from the mean.
#7
What is the formula for calculating the variance of a data set?
Sum of squares of differences between each value and the mean, divided by the count of numbers
ExplanationIt's the average of the squared differences from the mean.
#8
In a normal distribution, what percentage of data falls within one standard deviation of the mean?
68%
ExplanationAbout two-thirds of the data falls within one standard deviation of the mean.
#9
What does 'correlation coefficient' measure?
Strength and direction of the linear relationship between two variables
ExplanationIt indicates how closely two variables are related.
#10
What does the 'P-value' represent in hypothesis testing?
Probability of observing a sample statistic as extreme as the one computed
ExplanationIt helps determine the strength of evidence against the null hypothesis.
#11
What is the formula for calculating covariance between two variables?
Product of differences between corresponding values and their means
ExplanationIt measures how two variables change together.
#12
Which of the following is a measure of skewness?
Coefficient of skewness
ExplanationIt quantifies the asymmetry of the distribution of a random variable.
#13
What is the formula for calculating the coefficient of variation?
Standard deviation divided by the mean, multiplied by 100
ExplanationIt standardizes the measure of dispersion by expressing it as a percentage.
#14
What is the central limit theorem?
States that the larger the sample size, the closer the sample mean approaches the population mean
ExplanationIt explains how the distribution of sample means approaches a normal distribution.