Measuring lung function:One of the measurements used to determine the health of a person's lungs is the amount of air a person can exhale under force in one second. This is called the forced expiratory volume in one second, and is abbreviated

FEV1

. Assume the mean

FEV1

for

10

-year-old boys is

2.1

liters and that the population standard deviation is

=0.4

. A random sample of

54

10

-year-old boys who live in a community with high levels of ozone pollution is found to have a sample mean

FEV1

of

1.95

liters. Can you conclude that the mean

FEV1

in the high-pollution community differs from

2.1

liters? Use the

=0.10

level of significance and the critical value method with the table.

Part 1 of 5

(a) State the appropriate null and alternate hypotheses.

:H0

=2.1

:H1

2.1

This hypothesis test is a two-tailed test.

Part:1 / 5

1 of 5 Parts Complete

Part 2 of 5

Find the criticalvalue(s).Round the answer(s) to three decimalplaces,ifnecessary.If there is more than one criticalvalue,separate them withcommas.

Critical value(s):