#1
Which statistical measure best represents the central tendency of a dataset?
Mean
ExplanationMean is the arithmetic average of a dataset, providing a measure of central tendency.
#2
In a scatter plot, what does a negative correlation between two variables indicate?
As one variable increases, the other variable decreases
ExplanationNegative correlation suggests that as one variable increases, the other tends to decrease.
#3
Which data visualization technique is suitable for displaying the distribution of a single continuous variable?
Histogram
ExplanationHistograms are effective for illustrating the distribution of a single continuous variable.
#4
Which statistical test is appropriate for comparing the means of two independent groups?
t-test
ExplanationThe t-test is suitable for comparing means of two independent groups to assess if they are significantly different.
#5
What is the purpose of a residual plot in regression analysis?
To identify outliers and patterns in the residuals
ExplanationResidual plots help detect outliers and patterns in the discrepancies between predicted and actual values.
#6
Which method is commonly used for smoothing out noisy data in time series analysis?
Moving Average
ExplanationMoving Average is a common technique for smoothing out fluctuations in time series data.
#7
What is the formula for calculating correlation coefficient?
Covariance(X,Y) / (Standard Deviation(X) * Standard Deviation(Y))
ExplanationCorrelation coefficient is calculated as the covariance of two variables divided by the product of their standard deviations.
#8
What does the slope of the regression line represent?
The average change in the dependent variable for a one-unit change in the independent variable
ExplanationThe slope of the regression line signifies the average change in the dependent variable for a unit change in the independent variable.
#9
What is the purpose of a covariance matrix in multivariate analysis?
To analyze the relationship between multiple variables
ExplanationCovariance matrix helps understand the relationships and variability between multiple variables.
#10
What does the p-value represent in hypothesis testing?
Probability of observing the data given that the null hypothesis is true
ExplanationThe p-value indicates the probability of obtaining the observed data if the null hypothesis is true.
#11
In time series analysis, what is autocorrelation?
The correlation between a variable and its lagged values
ExplanationAutocorrelation measures the correlation between a variable and its past values at different time lags.