Calcium is essential to tree growth because it promotes the formation of wood and maintains cell walls. In 1990, the concentration of calcium in precipitation in a certain area was 0.11 milligrams per liter (mg/L), A random sample of 10 precipitation dates in 2007 resu|ts in the following data table. Complete pans (a) through (c) below. a 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: p = 0.11mg/L H1: 1; # 0.11mg/L (h) Construct a 90% condence interval about the sample mean concentration of calcium precipitation, The lower bound is The upper bound is . (Round to four decimal places as needed.)