Calcium is essential to tree growth. In 1990, the concentration of calcium in precipitation in Chautauqua, New York, was 0.11 milligram per liter \( \left(\frac{\mathrm{mg}}{\mathrm{L}}\right) \). A random sample of 8 precipitation dates in 2018 results in the following data: \( 0.120 \quad 0.108 \) A normal probability plot suggests the data could come from a population that is normally distributed. A boxplot does not show any outliers. Does the sample evidence suggest that calcium concentrations have changed since 1990? Use the \( \mathrm{a}=0.1 \) level of significance.

A water bottling facility has a mean bottling rate of 33.5 thousand bottles per hour with a standard deviation of 1.92 thousand bottles. A nearby cola bottling facility has a mean bottling rate of 26.2 thousand bottles per hour with a standard deviation of 1.42 thousand bottles. One Wednesday from noon to \( 1: 00 \) p.m., the water bottling facility bottled 36.8 thousand bottles of water, and the cola bottling facility bottled 28.4 thousand bottles of cola. Which facility increased their efficiency more during that hour? Answer

A water bottling facility has a mean bottling rate of 35.2 thousand bottles per hour with a standard deviation of 2.04 thousand bottles, A nearby cola bottling facility has a mean bottling rate of 26.9 thousand bottles per hour with a standard deviation of 1.51 thousand bottles. One Wednesday from noon to \( 1: 00 \) p.m., the water bottling facility bottled 36.9 thousand bottles of water, and the cola bottling facility bottled 27.9 thousand bottles of cola. Which facility increased their efficiency more during that hour? Answer

Construct a box plot from the given data. Diameters of Cans in an Assembly Line: \( 5.8,5.7,5.2,5.5,5.3,5.7,5.8,5.4,5.9,5.3 \)

The grades on the second statistics test for Ms. Rose's class are in the following list. Find the frequency distribution for the grades. B, B, A, D, D, D, D, C, C, D, F, D, D, D, D, B, C, B, F, F, C

Scores on a test have a mean of 78 and a standard deviation of 13 . Tom has a score of 66 . Convert Tom's score to a \( z \)-score, rounded to the nearest hundredth.