Statistics and Probability (Q4 Reviewer)

Complete Name

Section

• Duterte
• Marcos
• Aquino

1. What is the primary purpose of setting a level of significance in hypothesis testing?

• A) To determine the sample size required for the study
• B) To calculate the probability of the null hypothesis being true
• C) To establish a benchmark for rejecting the null hypothesis
• D) To identify the type of error that may occur in the test

2. What type of error occurs when a researcher rejects a true null hypothesis?

• A) Type I error
• B) Type II error
• C) Alpha error
• D) Beta error

3. Suppose we want to test the hypothesis that the mean score of a new exam is higher than 80. We set α = 0.05 and conduct a sample test, resulting in a sample mean of 82. Using a statistical software, we find that the p-value is 0.03. If we reject the null hypothesis, what is the probability of committing a Type I error?

• A) 0.03
• B) 0.05
• C) 0.95
• D) 0.97

4. A company claims that the average lifespan of their light bulbs is 1,000 hours. What is the parameter to be tested in this scenario?

• A) Standard deviation of light bulb lifespan
• B) Mean lifespan of light bulbs
• C) Median lifespan of light bulbs
• D) Mode of light bulb lifespan

5. A survey finds that 60% of customers prefer a certain brand of coffee. What is the parameter to be tested in this scenario?

• A) Proportion of customers who prefer the brand
• B) Mean rating of the coffee brand
• C) Standard deviation of customer preferences
• D) Mode of customer preferences

6. A researcher wants to test whether the average salary of employees in a company is higher than Php50,000. What are the appropriate null and alternative hypotheses?

• A) H0: μ = 50,000, H1: μ < 50,000
• B) H0: μ = 50,000, H1: μ > 50,000
• C) H0: μ ≠ 50,000, H1: μ = 50,000
• D) H0: μ ≤ 50,000, H1: μ ≥ 50,000

7. A study wants to investigate whether the average weight of a new breed of chicken is different from 2.5 kg. What are the appropriate null and alternative hypotheses?

• A) H0: μ = 2.5, H1: μ ≠ 2.5
• B) H0: μ ≠ 2.5, H1: μ = 2.5
• C) H0: μ < 2.5, H1: μ > 2.5
• D) H0: μ > 2.5, H1: μ < 2.5

8. When testing a population mean, what is the appropriate form of the test-statistic when the population variance is assumed to be known?

• A) t = (x̄ - μ) / (s / √n)
• B) z = (x̄ - μ) / (σ / √n)
• C) t = (x̄ - μ) / (σ / √n)
• D) F = (x̄ - μ) / (s / √n)