A recent study reported that Americans spend an average of 270 minutes per day watching TV. Assume the distribution of minutes per day watching TV follows a normal distribution with a standard deviation of 23 minutes. a. What percent of the population watch more than 300 minutes per day? (Round your intermediate calculations and final answer to 2 decimal places.) Population watching TV more than 300 minutes per day % b. What percent of the population watch more than 220 minutes per day? (Round your intermediate calculations and final answer to 2 decimal places.) Population watching TV more than 220 minutes per day % c. What percent of the population watch between 220 hours and 300 hours? (Round your intermediate calculations and final answer to 2 decimal places.) Population watching TV between 220 hours and 300 hours

Use the magnitudes (Richter scale) of the 120 earthquakes listed in the accompanying data table. Use technology to find the range, variance, and standard deviation. If another value, 8.00, is added to those listed in the data set, do the measures of variation change much? Click the icon to view the table of magnitudes. Magnitudes Without the extra data value, the range is (Type an integer or decimal rounded to three decimal places as needed.) 3.28 2.82 2.83 1.96 1.70 2.55 O 2.45 3.40 3.95 1.59 2.91 1.63 2.53 2.42 2.97 2.93 3.99 2.54 2.43 1.83 2.17 2.35 2.00 3.01 2.80 3.86 2.93 2.08 1.86 2.35 2.38 3.45 3.43 1.55 2.54 1.49 2.19 3.09 2.28 3.25 1.98 1.91 2.42 2.95 2.14 2.33 2.56 2.89 1.48 1.91 2.68 1.81 3.65 2.70 1.45 3.61 3.14 2.57 1.51 1.41 2.83 2.87 2.18 1.67 3.21 1.39 1.75 2.35 1.14 2.36 2.48 1.79 2.00 3.03 1.94 2.42 1.86 2.25 2.33 3.17 4.01 2.08 1.49 2.31 2.33 2.56 2.59 2.21 2.75 2.45 2.73 3.58 2.81 2.80 3.25 1.76 4.68 3.23 2.38 2.00 3.83 2.39 2.85 3.38 2.69 2.31 2.83 2.78 2.43 2.34…

instructor gives a 100-point examination in which the grades are normally distributed. The mean is 66 and the standard deviation is 5. If there are 5% A's and 5% F's, 15% B's and 15% D's, and 60% C's, find the scores that divide the distribution into those categories. Round the cutoff scores to the nearest whole number. Round intermediate z-value calculations to 2 decimal places. A:_- B: C: D: --- F: _-_

Jse the Empirical Rule. The mean speed of a sample of vehicles along a stretch of highway is 64 miles per hour, with a standard deviation of 4 miles per hour. Estimate the percent of vehicles whose speeds are between miles per hour and 72 miles per hour. (Assume the data set has a bell-shaped distribution.) Approximately % of vehicles travel between 56 miles per hour and 72 miles per hour.