Question

1) Find the critical values chi Subscript Upper R Superscript 2 and chi Subscript Upper L Superscript 2 for the given confidence level c and sample size n. c 0.90​, n=15

2) Use the confidence interval to find the margin of error and the sample mean. ( left 0.672,0.850 )

Answer 1

1)

Given that,

n = 15

Degrees of freedom = df = n - 1 = 14

²_L = ²_/2,df = 23.685

²_R = ²_{1 - /2,df} = 6.571

2)

Point estimate = = (Lower confidence interval + Upper confidence interval ) / 2

sample mean = = (0.672 + 0.850) / 2 = 0.761

Margin of error = E = Upper confidence interval - = 0.850 - 0.761 = 0.089