normal distribution

What does a 95% confidence level indicate?

That the method used will capture the true population parameter in 95% of repeated samples

In a normal distribution, where is the mean located?

At the center of the distribution

What shape best describes a normal distribution?

 A symmetric bell-shaped curve

In a normal distribution, which statement is TRUE about the mean, median, and mode?

The mean, median, and mode are all equal

What does the standard deviation represent in a normal distribution?

How far data values typically spread from the mean

What is the null hypothesis (H₀)?

A statement that there is no effect or no difference

What does a p-value represent?

The probability of obtaining results as extreme as those observed if H₀ is true

If p = 0.03 and α = 0.05, what is the correct decision?

Reject the null hypothesis

What does it mean when a result is statistically significant?

The result is unlikely to have occurred by random chance alone

Which statement best describes the alternative hypothesis (H₁)?

 It states that there is an effect, difference, or relationship

What is the meaning of a confidence interval?

A confidence interval provides a range of values that is likely to contain the true population parameter. It reflects the uncertainty involved in estimating a population value from sample data.

Why is the normal distribution important in statistics?

The normal distribution is important because many real-world variables approximately follow this pattern. It allows researchers to apply standard probability rules and statistical tests.

What does it mean to “reject the null hypothesis”?

Rejecting the null hypothesis means that the sample data provide sufficient evidence against it. This indicates that the result is statistically significant.

How does the confidence level affect the width of a confidence interval?

A higher confidence level results in a wider confidence interval to increase the likelihood of capturing the true population parameter. A lower confidence level produces a narrower interval with less certainty.

What is the role of the alternative hypothesis in hypothesis testing?

The alternative hypothesis states that there is an effect, difference, or relationship in the population. It represents the claim that is supported when the null hypothesis is rejected.