8. A random sample of 425 JAC students found that the average number of caffeinated drinks consumed per day was 2.8 with s=0.32. a. Calculate a 95% confidence interval. b. Interpret.

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A random sample of 425 JAC students found that the average number of caffeinated drinks
consumed per day was 2.8 with s=0.3.

 

a. Calculate a 95% confidence interval.

b. Interpret.

**Question 8: Statistical Analysis of Caffeinated Drink Consumption**

A study involving a random sample of 425 JAC students revealed that the average number of caffeinated drinks consumed per day was 2.8, with a standard deviation (s) of 0.32.

**a. Calculate a 95% Confidence Interval**

- To calculate a 95% confidence interval for the average number of caffeinated drinks consumed per day, use the formula for the confidence interval of the mean:
  \[
  \text{CI} = \bar{x} \pm z\left(\frac{s}{\sqrt{n}}\right)
  \]
  where:
  - \(\bar{x} = 2.8\) (sample mean)
  - \(z\) is the z-value for a 95% confidence level (typically 1.96)
  - \(s = 0.32\) (standard deviation)
  - \(n = 425\) (sample size)

**b. Interpret**

- Explain the meaning of the calculated confidence interval in the context of the study and what it implies about the population mean. The interval gives a range within which we can be 95% confident that the true average number of caffeinated drinks consumed per day by all JAC students falls.
Transcribed Image Text:**Question 8: Statistical Analysis of Caffeinated Drink Consumption** A study involving a random sample of 425 JAC students revealed that the average number of caffeinated drinks consumed per day was 2.8, with a standard deviation (s) of 0.32. **a. Calculate a 95% Confidence Interval** - To calculate a 95% confidence interval for the average number of caffeinated drinks consumed per day, use the formula for the confidence interval of the mean: \[ \text{CI} = \bar{x} \pm z\left(\frac{s}{\sqrt{n}}\right) \] where: - \(\bar{x} = 2.8\) (sample mean) - \(z\) is the z-value for a 95% confidence level (typically 1.96) - \(s = 0.32\) (standard deviation) - \(n = 425\) (sample size) **b. Interpret** - Explain the meaning of the calculated confidence interval in the context of the study and what it implies about the population mean. The interval gives a range within which we can be 95% confident that the true average number of caffeinated drinks consumed per day by all JAC students falls.
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