Question

The following n = 10 observations are a sample from a normal population.

7.4    7.0    6.5    7.5    7.6    6.2    6.8    7.7    6.4    6.9

(a) Find the mean and standard deviation of these data. (Round your standard deviation to four decimal places.)

mean
standard deviation

(b) Find a 99% upper one-sided confidence bound for the population mean μ. (Round your answer to three decimal places.)


(c) Test H₀: μ = 7.5 versus H_a: μ < 7.5. Use α = 0.01.

State the test statistic. (Round your answer to three decimal places.)

t =

State the rejection region. (If the test is one-tailed, enter NONE for the unused region. Round your answers to three decimal places.)

t >

t <

Answer 1

a) mean =7.00

standard deviation =0.5333

b)

std error sx=s/√n=

0.1687

for 99% upper CI; and 9 df, critical t=		2.8214
margin of error E=t*std error                            =		0.476

Upper bound=sample mean+E=

7.476

c)

test stat t='(x-μ)*√n/s=

-2.965

rejection region

t > NONE

t<-2.821