For the following 4 questions, report the answers to the nearest 0.001. Imagine that we take a sample from a population of interest. Sample data For the following questions use the sample values to the right: 21 17 17 21 Assume that this sample accurately reects the mean and standard 15 18 deviation of the population so you can use the normal distribution and 18 22 2 scores for the problems below. (If you've read ahead in your book or lab manual you know we should really use t soores, don't worry about this right now, use the 2 scores) Q8. Assuming that the population data is normally distributed, what is the value Val. = ? that you expect 67% of the data in the population to be smaller than? Q9. What is your best estimate for the IQR of the population data? IQR = ? Now, using the sample statistics as estimates of the population parameters and the normal distribution (i.e., don't use the t-distribution), calculate the symmetric region that you predict will encompass the middle 95% of the population. What are the lower and upper bounds of this region? Q10. What is the lower edge of this region? Lower = ? Q11. What is the upper edge of this region? Upper = ? For the following numerical questions on this page, report the answers to the nearest 0.001. Consider the sample: 22 , 19 , 21 , 23 , 29 , 30 , 33 , 18 , 23 , 25 , 29 , 27 , 34 , 31 Q12. What is the standard error for this sample? SE = ? Q13-14. Provide the values for the lower and upper values for Lower value = ? the 95% confidence interval of the population mean. Upper value = ? Q15. If someone claimed that the mean of the population this sample came from was 28, what would you think about that claim? Your choices: () There's no reason to decide the claim isn't true since that value is outside the 95% confidence interval. There's no reason to decide the claim isn't true since that value is within the 95% confidence interval. () The claim is unlikely to be true since that value is outside the 95% confidence interval. () The claim is unlikely to be true since that value is within the 95% confidence interval