Data Science Analysis 4

Question 1

In hypothesis testing, what does a p-value of 0.03 mean at the 0.05 significance level?

Accepted Answer

Reject the null hypothesis

Answer

Fail to reject the null hypothesis

Answer

The null hypothesis is proven true

Answer

The alternative is proven false

Question 2

What does a 95% confidence interval for a mean represent?

Accepted Answer

A range that would contain the true mean in 95% of repeated samples

Answer

The range of all data values

Answer

A guarantee the mean is in it

Answer

The standard deviation of the data

Question 3

A Type I error in hypothesis testing is:

Accepted Answer

Rejecting a true null hypothesis (false positive)

Answer

Failing to reject a false null (false negative)

Answer

Choosing the wrong test statistic

Answer

Using too large a sample

Question 4

Increasing the sample size generally has what effect on the standard error of the mean?

Accepted Answer

It decreases

Answer

It increases

Answer

It stays exactly the same

Answer

It becomes negative

Question 5

Which test compares the means of two independent groups?

Accepted Answer

Independent samples t-test

Answer

Chi-square test of independence

Answer

Pearson correlation

Answer

Shapiro-Wilk test

Question 6

The Central Limit Theorem states that the sampling distribution of the mean:

Accepted Answer

Approaches normal as sample size grows, regardless of population shape

Answer

Is always identical to the population distribution

Answer

Only applies to normal populations

Answer

Has increasing variance with larger samples

Question 7

A chi-square test of independence is used to assess:

Accepted Answer

Association between two categorical variables

Answer

The mean of a continuous variable

Answer

Linear correlation strength

Answer

Differences in variance