A z test of H₀: μ = μ₀ against H₁: μ < μ₀ gives the test statistic z = −1.36. Find the p-value p.
Hypothesis tests & confidence intervals worksheet with answers
A machine is supposed to fill bottles with 100 mL on average. The standard deviation is known to be 20 mL. A sample of 49 bottles has a mean of 103.4 mL. Find the test statistic z for H₀: μ = 100.
The mean of a population is claimed to be 120; the population standard deviation is known to be 12. A random sample of 36 observations has a mean of 124.36. Test H₀: μ = 120 against H₁: μ ≠ 120. Find the p-value p.
A sample of 64 students has a mean score of 496.6 and a sample standard deviation of 15. Find the test statistic t for H₀: μ = 500.
A one-sided z test at α = 0.05 must detect a shift of the mean of 3 units with a power of 95%. The standard deviation is 8. Find the minimum sample size n.
A sample of 100 measurements has mean 118.8. The population standard deviation is 5. Find the lower limit L of the 90% confidence interval for the mean.
Answer key
- 1. p = 0.08692
- 2. z = 1.19
- 3. p = 0.02926
- 4. t = −1.813
- 5. n = 77
- 6. L = 118
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