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2.5 Statistical Hypothesis Testing

2.5 Statistical Hypothesis Testing

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Question 80

In a bioreactor, the dissolved oxygen concentration CCC (mg/L) follows a normal distribution C∼N(μ,σ2)C \sim \mathrm{N}(\mu, \sigma^2)C∼N(μ,σ2). Based on a random sample of measurements, an 80% confidence interval for μ \mu\,μ is determined to be (18.0155,18.7845)(18.0155, 18.7845)(18.0155,18.7845).

a.

Determine a 95% confidence interval for the mean dissolved oxygen concentration μ\muμ.

[4]
b.

The total oxygen content in a specific tank volume is given by the linear relationship Q=2.5C+4Q = 2.5C + 4Q=2.5C+4. Using your answer to part (a), calculate a 95% confidence interval for the mean oxygen content μQ\mu_QμQ​.

[2]
c.

Five independent random samples are collected from different bioreactors with the same mean μ\muμ. A 95% confidence interval for μ \mu\,μ is calculated for each sample. Find the probability that at least four of these five intervals will capture the true value of μ\muμ.

[3]
Markscheme

2.5 Statistical Hypothesis Testing Questions

  1. A Level
  2. /Maths
  3. /2.5 Statistical Hypothesis Testing

316 exam-style questions on OCR A Level Maths 2.5 Statistical Hypothesis Testing, covering 2.5.1 The language of hypothesis testing, 2.5.2 Hypothesis test for a binomial proportion, 2.5.3 Inference and significance level, 2.5.4 Sample mean as a random variable (A-level only), 2.5.5 Hypothesis test for the mean of a normal distribution (A-level only), 2.5.6 Pearson's product-moment correlation coefficient, and 2.5.7 Hypothesis test using Pearson's coefficient (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

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