1. A sample of 49 observations is taken from a normal population with a standard deviation of 10. The sample mean is 55. Determine the 99% confidence interval for the population mean. (Round your answers to 2 decimal places.) Confidence interval for the population mean is and . A research firm conducted a survey to determine the mean amount steady smokers spend on cigarettes during a week. They found the distribution of amounts spent per week followed the normal distribution with a population standard deviation of $5. A sample of 64 steady smokers revealed that X=$20. a. What is the 95% confidence interval estimate of ? (Round your answers to 3 decimal places.) Confidence interval is between $ and $ .
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For the first question, we are given that the sample size (n) is 49, the sample mean (x̄) is 55, and the standard deviation (σ) is 10. We are asked to find the 99% confidence interval for the population mean (μ). The formula for a confidence interval is x̄ ± Show more…
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1. A sample of 49 observations is taken from a normal population with a standard deviation of 10. The sample mean is 55. Determine the 99% confidence interval for the population mean. (Round your answers to 2 decimal places.) Confidence interval for the population mean is and . 2. A research firm conducted a survey to determine the mean amount steady smokers spend on cigarettes during a week. They found the distribution of amounts spent per week followed the normal distribution with a population standard deviation of $5. A sample of 64 steady smokers revealed that . a. What is the 95% confidence interval estimate of ? (Round your answers to 3 decimal places.) Confidence interval is between $ and $ .
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