#1
What is the median of the following dataset: 12, 15, 18, 20, 25, 30, 35?
25
ExplanationMiddle value of the dataset; half of the values are above and half below.
#2
What does the term 'p-value' stand for in statistics?
Probability value
ExplanationProbability of obtaining results as extreme as the observed results.
#3
What does the term 'skewness' refer to in statistics?
The lack of symmetry in the distribution
ExplanationMeasure of asymmetry in the distribution of data.
#4
Which of the following is a measure of relative standing in a dataset?
Median
ExplanationMiddle value in a sorted list of values.
#5
Which statistical distribution is commonly used to model continuous random variables?
Normal distribution
ExplanationSymmetric, bell-shaped distribution.
#6
What is the standard deviation of the following dataset: 5, 10, 15, 20, 25, 30?
7.5
ExplanationMeasure of dispersion indicating the spread of values around the mean.
#7
What is the mode of the following dataset: 3, 5, 5, 7, 7, 7, 9, 9, 11?
7
ExplanationMost frequently occurring value in the dataset.
#8
Which measure of central tendency is affected most by outliers?
Mean
ExplanationSensitive to extreme values, pulling the average towards them.
#9
Which graphical representation is used to display the relationship between two continuous variables?
Scatter plot
ExplanationShows how one variable is affected by another.
#10
What is the purpose of hypothesis testing in statistical analysis?
To make inferences about population parameters based on sample data
ExplanationDetermines if there is enough evidence to reject a null hypothesis.
#11
In a normal distribution, what percentage of data falls within one standard deviation from the mean?
68.3%
ExplanationApproximately 68.3% of data points fall within one standard deviation of the mean.
#12
What is the purpose of a histogram in statistical analysis?
To visualize the frequency distribution of a continuous variable
ExplanationShows the distribution of a continuous variable.
#13
In a box plot, what does the line inside the box represent?
The median
ExplanationMiddle value of the dataset.
#14
Which of the following statistical tests is used to determine if there is a significant difference between the means of more than two independent groups?
Analysis of variance (ANOVA)
ExplanationDetermines if there are any statistically significant differences between group means.
#15
What does the term 'confidence interval' represent in statistics?
The range of values within which the true population parameter is estimated to lie
ExplanationRange of values within which the population parameter is likely to be.
#16
What is the coefficient of correlation if the correlation between two variables is perfect and positive?
1
ExplanationIndicates a perfect positive linear relationship between variables.
#17
Which of the following statistical tests is used to compare the means of two independent groups?
T-test
ExplanationDetermines if there is a significant difference between means of two groups.
#18
What does a p-value indicate in hypothesis testing?
The probability of observing the sample data given that the null hypothesis is true
ExplanationProbability of obtaining test results at least as extreme as the observed results.
#19
What does the standard error measure in statistical analysis?
The variability of sample means around the population mean
ExplanationEstimate of how much the sample mean is likely to differ from the population mean.
#20
Which of the following measures of dispersion is least affected by outliers?
Interquartile range
ExplanationSpread of middle 50% of data; outliers have less influence.
#21
Which of the following is NOT a measure of association used in regression analysis?
F-test statistic
ExplanationStatistical test for comparing statistical models.
#22
What is the formula to calculate the coefficient of variation?
(Standard Deviation / Mean) * 100
ExplanationMeasures the ratio of the standard deviation to the mean.
#23
What does the term 'Type I error' represent in hypothesis testing?
Rejecting the null hypothesis when it is true
ExplanationIncorrectly rejecting a true null hypothesis.
#24
What is the formula for calculating the coefficient of determination (R-squared) in linear regression?
1 - (SSE / SST)
ExplanationProportion of the variance in the dependent variable that is predictable.
#25
What is the formula to calculate the z-score of a data point in a normal distribution?
(x - μ) / σ
ExplanationStandardized measure indicating how many standard deviations a data point is from the mean.