A z test of H₀: μ = μ₀ against H₁: μ ≠ μ₀ gives the test statistic z = 1.01. Find the p-value p.
Hypothesis tests & confidence intervals worksheet with answers
A machine is supposed to fill bottles with 50 mL on average. The standard deviation is known to be 10 mL. A sample of 64 bottles has a mean of 47.25 mL. Find the test statistic z for H₀: μ = 50.
Two teaching methods are compared. Group 1: 5 students, mean score 116, standard deviation 4. Group 2: 7 students, mean score 135.7, standard deviation 12. Assume equal population variances and use the pooled two-sample t test. Find the test statistic t for H₀: μ₁ = μ₂, taking the difference as x̄₁ − x̄₂ (group 1 minus group 2).
A sample of 49 students has a mean score of 197.9 and a sample standard deviation of 8. Find the test statistic t for H₀: μ = 200.
A sample of 64 measurements has mean 44.6. The population standard deviation is 15. Find the lower limit L of the 99% confidence interval for the mean.
A sample of 64 measurements has mean 73.2. The population standard deviation is 8. Find the upper limit U of the 95% confidence interval for the mean.
Answer key
- 1. p = 0.3125
- 2. z = −2.2
- 3. t = −3.492
- 4. t = −1.837
- 5. L = 39.77
- 6. U = 75.16
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