Question

Question 3 2 A psychiatrist is interested in finding a 95% confidence interval for the tics per hour exhibited by children with Tourette syndrome. The data below show the tics in an observed hour for 12 randomly selected children with Tourette syndrome. 8 7 11 10 2 41 11 7 66 Round answers to 3 decimal places where possible. Sus Question 4 1 p You want to compute a 98% confidence interval for a population mean. Assume that the population standard deviation is known to be 10 and the sample size is 50. The critical value to be used in this

Answer 1

Confidence interval for Population mean is given as below:

Confidence interval = Xbar ± t*S/sqrt(n)

From given data, we have

Xbar = 5.333333333

S = 3.773913651

n = 12

df = n – 1 = 11

Confidence level = 95%

Critical t value = 2.2010

(by using t-table)

Confidence interval = Xbar ± t*S/sqrt(n)

Confidence interval = 5.333333333 ± 2.2010*3.773913651/sqrt(12)

Confidence interval = 5.333333333 ± 2.2010*1.089435031

Confidence interval = 5.333333333 ± 2.3978

Lower limit = 5.333333333 - 2.3978 = 2.936

Upper limit = 5.333333333 + 2.3978 = 7.731

Confidence interval = (2.936, 7.731)

2.936 ≤ µ ≤ 7.731