Cell Phone Radiation. Listed below are amounts of cell phone radiation (W, kg) measured from randomly selected cell phones (based on data from the Federal Communications Commission). Use these values for Exercises 1–6. 1.5 0.9 1.3 1.5 1.3 1.2 1.4 1.1 1.3 1.4 1.2 1. Statistics Find the mean, median, standard deviation, variance, and range. Are the results statistics or parameters? 2. Significance Use the results from Exercise 1 with the range rule of thumb to find amounts of radiation separating those that are significantly low and those that are significantly high. Is the lowest listed value significantly low? 3.Level of Measurement What is the level of measurement of these data (nominal, ordinal, interval, ratio)? Are the original unrounded amounts of radiation continuous data or discrete data? 4. Normality The accompanying graphs are a normal quantile plot and a histogram of the radiation amounts. What do these graphs suggest about the distribution of the population of cell phone radiation amounts? Cumulative Review Exercises 5.Confidence Interval Use the radiation amounts to construct a 95% confidence interval estimate of the population mean m. Write a brief statement that interprets that confidence interval. 6.Sample Size Find the sample size necessary to estimate the mean amount of cell phone radiation. Assume that we want 95% confidence that the sample mean is in error by no more than 0.05 W>kg. Based on a larger sample than the one given for the preceding exercises, assume that all cell phones have a standard deviation of 0.29 W>kg. 7.Normal Distribution Using a larger data set than the one given for the preceding exercises, assume that cell phone radiation amounts are normally distributed with a mean of 1.17 W>kg and a standard deviation of 0.29 W>kg. a. Find the probability that a randomly selected cell phone has a radiation amount that exceeds the U.S. standard of 1.6 W>kg or less. b. Find the value of Q3, the cell phone radiation amount that is the third quartile. 8.Controversial Song The song “Baby It’s Cold Outside” generated much controversy because of its lyrics and tone. CBS New York conducted a survey by asking viewers to use the Internet to respond to a question asking whether that song was really too offensive to play. Among 1043 Internet users who chose to respond, 986 said that the song was not too offensive, and 57 of the respondents said that the song was too offensive. a. Construct a 95% confidence interval estimate of the proportion of the population having the belief that the song is not too offensive. CHAPTER 7 Cumulative Review Exercises 367 continued
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