Data Science Statistical Concepts and Analysis 5

Question 1

Bayes' theorem allows you to update which quantity given new evidence?

Accepted Answer

The prior probability into a posterior probability

Answer

The sample mean into the population mean

Answer

The variance into the standard deviation

Answer

The median into the mode

Question 2

Overfitting in a statistical model means the model:

Accepted Answer

Fits training noise and generalizes poorly to new data

Answer

Is too simple to capture the pattern

Answer

Has too few parameters

Answer

Ignores the training data

Question 3

Which measure is most appropriate for describing the spread of a skewed distribution?

Accepted Answer

Interquartile range

Answer

Standard deviation

Answer

Mean

Answer

Mode

Question 4

In hypothesis testing, increasing the sample size generally:

Accepted Answer

Increases statistical power

Answer

Increases the Type I error rate

Answer

Widens confidence intervals

Answer

Reduces the test's reliability

Question 5

A residual in regression is defined as:

Accepted Answer

The difference between an observed and predicted value

Answer

The slope coefficient

Answer

The correlation of predictors

Answer

The mean of the outcome variable

Question 6

Which of these is a discrete random variable?

Accepted Answer

Number of customers arriving per hour

Answer

Exact height of a person

Answer

Time to complete a task

Answer

Weight of a package in kilograms

Question 7

What does stratified sampling improve compared to simple random sampling?

Accepted Answer

Representation of key subgroups within the population

Answer

The speed of data entry

Answer

The size of the population

Answer

The need for any randomness