#1
What is the mean of a probability distribution?
The average value
ExplanationAverage of all possible outcomes.
#2
What is the formula for calculating the median of a dataset?
Middle value when the data is arranged in ascending order
ExplanationMiddle value of a sorted dataset.
#3
What is the mode of a dataset?
The most frequently occurring value
ExplanationValue with the highest frequency in a dataset.
#4
What is the interquartile range (IQR) in statistics?
The range between the first and third quartiles
ExplanationSpread of the middle 50% of data.
#5
In a box plot, what does the box represent?
The interquartile range
ExplanationSpread of the middle 50% of data.
#6
What is the formula for calculating the variance of a dataset?
Sum of squared differences between each data point and the mean
ExplanationMeasure of data dispersion around the mean.
#7
In statistics, what does 'skewness' measure?
The symmetry of a distribution
ExplanationDegree of asymmetry in a distribution.
#8
What does the standard deviation represent in a normal distribution?
The spread of data around the mean
ExplanationMeasure of the dispersion of data points around the mean.
#9
Which of the following is a characteristic of a positively skewed distribution?
Mean < Median < Mode
ExplanationOrdering of central tendency measures.
#10
What does the term 'outlier' refer to in statistics?
A data point that is significantly different from other observations
ExplanationObservation distant from other data points.
#11
Which measure of central tendency is affected most by outliers?
Mean
ExplanationCentral tendency measure sensitive to extreme values.
#12
What is a p-value in hypothesis testing?
The probability of observing a test statistic as extreme or more extreme than the one observed, assuming the null hypothesis is true
ExplanationProbability of observing test results under the null hypothesis.
#13
What is the concept of kurtosis in statistics?
It measures the peakedness of a distribution
ExplanationDegree of peakedness of a distribution.
#14
What is the purpose of a Q-Q plot in statistics?
To assess the normality of a distribution
ExplanationVisual assessment of data normality.
#15
What is the purpose of a probability density function (PDF) in statistics?
To estimate probabilities of continuous random variables
ExplanationFunction describing the likelihood of continuous random variables.
#16
What is a Type I error in hypothesis testing?
Rejecting the null hypothesis when it is true
ExplanationIncorrectly rejecting a true null hypothesis.
#17
What does the term 'heteroscedasticity' refer to in regression analysis?
Unequal variance of the errors in a regression model
ExplanationVarying spread of residuals across levels of predictor variables.