STATISTICS & PROBABILITY EXAM

What is the method of testing a claim or hypothesis about a parameter in a population given a data sample?

• Sample analysis
• Hypothesis testing
• Parameter testing
• Population estimation

When is a z-test appropriate to use in hypothesis testing?

• When the sample size is large and the population standard deviation is known.
• When the sample size is small and the population standard deviation is known.
• When the sample size is small and the population standard deviation is unknown.
• When the sample size is large and the population standard deviation is unknown.

What is the appropriate test statistic to use when the population standard deviation is unknown and the sample size is less than 30?

• f-distribution
• chi-square distribution
• z-distribution
• t-distribution

What is the significance of the Central Limit Theorem in statistical analysis?

• 
  To ensure the test statistic has a standard normal distribution

• To guarantee that the sample size is always large enough for accurate results
• To limit the number of hypothesis tests that can be conducted
• To ensure that the population distribution is not normally skewed

In a z-test, what is calculated with population parameters such as population mean and population standard deviation?

• p-value
• t-score
• z-score
• confidence interval

What is the statistical term used to represent the likelihood of obtaining a sample mean that is at least as extreme as the one obtained, assuming the null hypothesis is true?

• confidence interval
• standard deviation
• alpha value
• p-value

When is a t-test used in hypothesis testing?

• When the sample size is large

• When the population variance or standard deviation are not known

• When the population variance is known

• When the population standard deviation is known

In the given situation below, identify the population standard deviation. “In a recent survey, the average amount of money a college student gets is ₱200.00 with a standard deviation of ₱62.00. A teacher feels that the average amount is higher. She surveys 80 randomly selected students and finds that the average amount is ₱245.”

• 𝜎 = ₱200

• 𝜎 = ₱62.00.

• 𝜎 = ₱245.00.

• The population standard deviation is not applicable.

What is the level of significance if the confidence interval is 90%?

• 20%
• 10%
• 15%
• 5%

“There are 9 students who will be taking up the test, the researcher sets the level of significance to 0.05. The following are the scores of nine students in the test:

23, 25, 25, 26, 27, 28, 30, 40, 45
What will be the t-value of the given problem?

• 1.456

• 1.23
• 1.729

• 2.75