A psychology professor of a large class became curious as to whether the student

Question

A psychology professor of a large class became curious as to whether the students who turned in tests first scored differently from the population mean score on the test. The overall test population standard deviation was 10: the scores were approximately normally distributed. The mean score for the first 20 students to turn in tests was 78. a. Should you use normal or Student-t distribution tables for this scenario? Be sure to include the reason for your choice. b. Use a 90% confidence level to calculate error bound EBM = ______ c. State the 90% confidence interval for the true population mean score of the test. CI = ______

Explanation / Answer

6) a) as we know the population std deviation and distribution is approximately normal ; therefore we can use normal distribution

b) here std error of mean =std deviaiton/(n)1/2 =10/(20)1/2 =2.236

for 90% CI ; z=1.645

therefore error bound =z*std error =3.678

c) 90% confidence interval =sample mean -/+ error bound =74.322 ; 81.678

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.