Calciumis essential to tree growth because it promotes the formation of wood andmaintains cell walls. In 1990, the concentration of calcium in precipitation ina certain area was 0.15 milligrams per liter (mg/L). A random sample of 10precipitation dates in 2007 results in the following data table

:0.074 0.078 0.059 0.254 0.114 0.171 0.103 0.239 0.306 0.109

a) Construct a 90% confidence interval about the sample mean concentration ofcalcium precipitation: (____,____) (use ascending order, round to four decimalplaces)

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

a. No, because the confidence interval does not contain 0.15 mg/L

b. Yes, because the confidence interval does not contain 0.15 mg/L

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