Introduction to the Practice of Statistics 9th edition by David S. Moore Test bank

 A)0.9772.
 B)0.9549.
 C)0.9974.
 D)0.6826.
 E)0.0228.
 
 
220.In 1998 the World Health Organization reported the findings of a major study on the quality of blood pressure monitoring around the world. In its report it stated that for Canada the results for diastolic blood pressure had a mean of 78 mmHg and a standard deviation of 11 mmHg. Assuming that diastolic blood pressure measurements are Normally distributed, the DBP reading that represents the 80th percentile of the distribution is
 A)85.4.
 B)93.6.
 C)87.3
 D)86.8.
 E)68.8.
 
 
221.In the blood pressure study by the WHO, the mean systolic blood pressure in the United States was reported to be 120 mmHg. The 75th percentile of the distribution of SBP measurements was found to be 109.2 mmHg. From this, it can be determined that the SBP standard deviation s is
 A)9.4.
 B)16.0.
 C)5.5.
 D)10.8.
 E)It is not within ± 0.5 of any of the above.
 
 
222.A stemplot of a set of data is roughly symmetric, but a quantile plot does not show a straight line. What conclusion can we draw?
 A)The data are Normal but not standard Normal.
 B)The data are standard Normal.
 C)The data are not Normal.
 D)The data are Normal.
 
 
223.Consider the following Normal quantile plot.
 

 
What is the most striking feature of the plot?
 A)The granularity
 B)The strong skewness indicated by the plot
 C)The many outliers evident in the plot
 D)The fact that Y is categorical
 
 
224.A quantile plot of the horsepower of a sample of 65 cars is shown below.
 

Which of the following descriptions best describes the shape of the distribution of horsepower?
 A)Normal
 B)Normal with some outliers
 C)Left-skewed
 D)Right-skewed
 
 
225.Which of the following statements about Normal quantile plots is/are FALSE?
 A)In constructing a Normal quantile plot, each data point is plotted against its corresponding Normal score.
 B)The Normal quantile plot is a very useful graphical tool for assessing the adequacy of the Normal model.
 C)If the points on a Normal quantile plot lie close to a straight line, the plot indicates that the Normal model is an adequate representation for the data.
 D)Because you will see the usual mound-like appearance of the Normal distribution on a histogram, it is more helpful than the quantile plot for assessing Normality.
 E)On a quantile plot, outliers will appear as points that are far away from the overall pattern of the plot.
 
 
226.Battery packs in electric go-carts need to last a fairly long time. The runtimes (time until it needs to be recharged) of the battery packs made by a particular company are Normally distributed with a mean of 2 hours and a standard deviation of 20 minutes.  What percentage of these battery packs lasts longer than 3 hours?
 
 
227.Battery packs in electric go-carts need to last a fairly long time. The runtimes (time until it needs to be recharged) of the battery packs made by a particular company are Normally distributed with a mean of 2 hours and a standard deviation of 20 minutes.  What is the third quartile for the run-time distribution?
 
 
228.Battery packs in electric go-carts need to last a fairly long time. The runtimes (time until it needs to be recharged) of the battery packs made by a particular company are Normally distributed with a mean of 2 hours and a standard deviation of 20 minutes.  Battery packs that have a runtime in the highest 10% of the run-time distribution are highly sought after by go-cart drivers. How long does the battery pack have to last for it to fall in this highly sought-after class?
 
 
229.A machine fills 64-ouncejugs with detergent. Assume the distribution of the amount of detergent in these jugs is Normal. Under standard circumstances, the mean amount should be 64 ounces with a standard deviation of 0.4 ounces. A quality control inspector regularly checks the amount poured into the jugs to see if the machine needs an adjustment or not, which is needed when the machine either overfills or underfills the jugs.  If the machine is running on target, what proportion of jugs receives more than 65 ounces of detergent?
 
 
230.A machine fills 64-ouncejugs with detergent. Assume the distribution of the amount of detergent in these jugs is Normal. Under standard circumstances, the mean amount should be 64 ounces with a standard deviation of 0.4 ounces. A quality control inspector regularly checks the amount poured into the jugs to see if the machine needs an adjustment or not, which is needed when the machine either overfills or underfills the jugs.  The quality control inspector will adjust the machine if he finds too many jugs that fall in the most extreme 5% of the distribution. Most extreme is defined as either too little (bottom 2.5%) or too much (top 2.5%). If the machine is running on target, what are the bounds for which the machine will be classified as working fine?