Biostatistics Quiz

What does the standard deviation measure in a dataset?

• Central tendency

• Spread of data

• Correlation

• Reliability

Which type of data can take only whole numbers?

• Continuous

• Discrete

• Nominal

• Ordinal

What is the first step in hypothesis testing?

• Calculating the p-value

• Stating the null and alternative hypotheses

• Collecting data

• Choosing a statistical test

If a confidence interval for a mean difference includes 0, what does this imply?

• The null hypothesis is rejected.

• The difference is statistically significant.

• There is no evidence of a difference.

• The p-value is less than 0.05.

A dataset has a mean of 50 and a standard deviation of 10. Which value is two standard deviations above the mean?

• 60

• 70

• 80

• 90

A researcher performs a chi-square test and obtains a p-value of 0.08. What is the correct interpretation if the significance level is 0.05?

• Accept the alternative hypothesis.

• Fail to reject the null hypothesis.

• Reject the null hypothesis.

• Conclude that the results are significant.

Which type of bias occurs when participants drop out of a study at different rates based on exposure or outcome?

• Selection bias

• Information bias

• Recall bias

• Attrition bias

Which measure of central tendency is least affected by extreme values?

• Mean

• Median

• Mode

• Range

In a normal distribution, approximately what percentage of data falls within one standard deviation of the mean?

• 50%

• 68%

• 95%

• 99.7%

What type of variable is 'blood group'?

• Continuous

• Ordinal

• Nominal

• Interval