NTTF Statistics Quiz

Sum of squared deviations = 200, observations = 10. What’s the variance?

The Central Limit Theorem is useful because:

The standard deviation can never be negative.

Correlation implies causation.

Which metric is most appropriate for identifying the presence of multicollinearity?

Which visualization is best suited to show the spread of a dataset?

Which measure best represents the 'spread' of a dataset?

Which statistic determines how far a point is from the mean in standard deviation units?

For a binomial distribution with n=10 and p=0.5, what is the expected value?

Which distribution is appropriate for modeling the number of events in a fixed interval of time or space?

Which of these statements is TRUE about confidence intervals?

A 95% confidence interval means there's a 95% chance the sample mean falls within it.

Which method is used to reduce dimensionality in datasets?

What is the primary purpose of sampling in statistics?

What is the mode of the dataset: [4, 4, 6, 7, 9, 4, 6]?

If the standard deviation is 5 and the mean is 20, what is the z-score of 30?

Which of these is an assumption of linear regression?

A z-score of 0 indicates that the data point is exactly at the mean.

Which of the following is a non-parametric test?

In a t-test, what does the 't' statistic represent?

Variance is the square root of the standard deviation.

The Central Limit Theorem says the sample mean is normally distributed, no matter the sample size.

What is the shape of a normal distribution?

The mean is always equal to the median in a normal distribution.

In linear regression, multicollinearity among predictors can affect the stability of coefficient estimates.

Skewness measures how flat or peaked a distribution is.

Which value of correlation coefficient indicates a perfect negative correlation?

What does skewness measure in a dataset?

Chi-square tests are used to compare means across multiple groups.

What does a p-value signify in hypothesis testing?

Which test is used to determine the goodness of fit for a categorical variable?

A distribution is symmetric if:

The range is affected by extreme values.

The area under a normal distribution curve is always equal to 1.

Which statistic is most sensitive to extreme values?

Which of the following tests would you use to compare means of more than two groups?

A Type I error occurs when we fail to reject a true null hypothesis.

Boxplots are useful for identifying outliers in a dataset.

In probability theory, which of these is NOT a valid probability?

Which of the following measures is NOT affected by outliers?

The mode is the most frequently occurring value in a dataset.

What does a 95% confidence interval mean?

A p-value less than 0.05 always proves the alternative hypothesis is true.