# Question: Refer to the Environmental Science Technology Jan 2005 study

Refer to the Environmental Science & Technology (Jan. 2005) study of the factors related to MTBE contamination in 223 New Hampshire wells, presented in Exercise. The data are saved in the MTBE file. Two of the many quantitative variables measured for each well are the pH level (standard units) and the MTBE level (micrograms per liter).

a. Construct a histogram for the pH levels of the sampled wells. From the histogram, estimate the proportion of wells with pH values less than 7.0.

b. For those wells with detectible levels of MTBE, construct a histogram for the MTBE values. From the histogram, estimate the proportion of contaminated wells with MTBE values that exceed 5 micrograms per liter.

c. Find the mean and standard deviation for the pH levels of the sampled wells, and construct the interval x-bar ± 2s. Estimate the percentage of wells with pH levels that fall within the interval. What rule did you apply to obtain the estimate? Explain.

d. Find the mean and standard deviation for the MTBE levels of the sampled wells, and construct the interval x-bar ± 2 s. Estimate the percentage of wells with MTBE levels that fall within the interval. What rule did you apply to obtain the estimate? Explain.

a. Construct a histogram for the pH levels of the sampled wells. From the histogram, estimate the proportion of wells with pH values less than 7.0.

b. For those wells with detectible levels of MTBE, construct a histogram for the MTBE values. From the histogram, estimate the proportion of contaminated wells with MTBE values that exceed 5 micrograms per liter.

c. Find the mean and standard deviation for the pH levels of the sampled wells, and construct the interval x-bar ± 2s. Estimate the percentage of wells with pH levels that fall within the interval. What rule did you apply to obtain the estimate? Explain.

d. Find the mean and standard deviation for the MTBE levels of the sampled wells, and construct the interval x-bar ± 2 s. Estimate the percentage of wells with MTBE levels that fall within the interval. What rule did you apply to obtain the estimate? Explain.

## Answer to relevant Questions

The distribution of scores on a nationally administered college achievement test has a median of 520 and a mean of 540. a. Explain why it is possible for the mean to exceed the median for this distribution of measurements. ...Clinical observations suggest that specifically language-impaired (SLI) children have great difficulty with the proper use of pronouns. This phenomenon was investigated and reported in the Journal of Communication Disorders ...Compute each of the following: a. b. c. d. e. An individual's genetic makeup is determined by the genes obtained from each parent. For every genetic trait, each parent possesses a gene pair, and each parent contributes one-half of this gene pair, with equal probability, ...A “handoff” is a term used in wireless communications to describe the process of a cell phone moving from a coverage area of one base station to another. Each base station has multiple channels (called color codes) that ...Post your question