Exam (elaborations) MATH221 Graded week 7 quiz (MATH221)MATH 221 Week 7 Quiz

(TCO 6) In the standard normal distribution, the standard deviation is always Student Answer: 0 1 2 none of these 2. Question : (TCO 6) The area under a normal curve with mu = 8 and sigma = 3 is Student Answer: 0 1 2 none of these 3. Question : (TCO 6) If Larry gets a 70 on a physics test where the mean is 65 and the standard deviation is 5.8, where does he stand in relation to his classmates? Student Answer: He is in the top 10%. He is in the top 20%. He is in the bottom 20%. He is in the bottom 10%. Hi there! Get instant help with MATH 221 Week 7 Quiz Without paying anything upfront. FREE QUOTE 4. Question : (TCO 6) In a normal distribution with mu = 25 and sigma = 6, what number corresponds to z = 3? Student Answer: 40 43 46 none of these 5. Question : (TCO 6) Let’s assume you have taken 100 samples of size 64 each from a normally distributed population. Calculate the standard deviation of the sample means if the population’s variance is 49. Student Answer: 0.875 0.125 0.766 0.587 6. Question : (TCO 6) The area to the left of ‘z’ is 0.9976. What z-score corresponds to this area? Student Answer: 2.85 -2.89 2.82 none of these 7. Question : (TCO 6) Find P(9 x 22) when mu = 20 and sigma = 5. Student Answer: 0.6554 0.6415 0.0139 0.3585 8. Question : (TCO 7) What is the critical z-value that corresponds to a confidence level of 86%? Student Answer: approximately 1.48 approximately 1.55 approximately 1.75 none of these 9. Question : (TCO 7) Compute the population mean margin of error for a 90% confidence interval when sigma is 4 and the sample size is 36.