Question

Sample mean:                         x̄ = 48.74  

Sample standard deviation:    s = 32.5857

Size of your sample:                n = 50

1.   What is your Point Estimate? (round each answer to at least 4 decimals)

            For a 90% confidence interval

Answer 1

Given that,

= 48.74

s =32.5857

n = 50

point estimate = 48.74

Degrees of freedom = df = n - 1 = 50- 1 = 49

At 90% confidence level the t is ,

= 1 - 90% = 1 - 0.90 = 0.1

/ 2 = 0.1 / 2 = 0.05

t _/2,df = t_0.05,49=1.677

Margin of error = E = t_/2,df * (s /n)

= 1.677* ( 32.5857/ 50) = 7.7281

The 90% confidence interval estimate of the population mean is,

- E < < + E

48.74   - 7.7281 < < 48.74  + 7.7281

71.0119< < 56.4681

( 71.0119, 56.4681)