A researcher is interested in determining the mean number of arrests among the population of prisoners in Texas following their release from prison. The researcher uses sample data from 200 people recently released from prison. She finds that the mean number of new arrests in her sample equals 7. The standard deviation for the population is equal to 2.5. A. What is the range of the mean number of arrests for which she can be 95% confident that the true population mean falls within the range? B.If the researcher wants to be 99% confident that the range contains the true population mean, what range of the mean number of arrests should she provide?
Added by Carla R.
Step 1
Since we know the sample size (n = 200), the sample mean (x̄ = 7), and the population standard deviation (σ = 2.5), we can use the following formula: Confidence interval = x̄ ± z*(σ/√n) where z is the z-score corresponding to the desired level of confidence. For Show more…
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