Calcium is essential to tree growth because it promotes the formation of wood and maintains cell walls. In1990, the concentration of calcium in precipitation in a certain area was 0.15 milligrams per liter(mg/L). A random sample of 10 precipitation dates in 2007 results in the following data table. Complete parts(a) through(c) below.

Click the icon to view the data table.

(a) State the hypotheses for determining if the mean concentration of calcium precipitation has changed since 1990.

H0: _____ _____0.15 mg/L

H1: _____ ______0.15 mg/L

First set of options

p

Second set of options

less than

<

not equals

equals

=

greater than

>

(b) Construct a 95% confidence interval about the sample mean concentration of calcium precipitation.

The lower bound is ______

The upper bound is ______

(Round to four decimal places asneeded.)

(c) Does the sample evidence suggest that calcium concentrations have changed since1990?

A.

No, because the confidence interval doesnotcontain 0.15 mg/L.

B.

Yes, because the confidence interval contains 0.15 mg/L.

C.

No, because the confidence interval contains 0.15 mg/L.

D.

Yes, because the confidence interval doesnotcontain 0.15 mg/L.