Blog

Client is about to go to trial on a criminal charge of burglary.  Lawyer has interviewed Client and learned that Client wishes to testify at trial that he was with his girlfriend at her apartment at the time of the crime.  Client tells Lawyer that he insists on testifying and he insists that his girlfriend be permitted to testify to corroborate the alibi.  Lawyer thinks the story is implausible and reasonably believes that both Client and girlfriend are lying.   What is the correct course of conduct for Lawyer?

There are 50 employees of the University of Cincinnati with the title “grant administrator.”  Here is a graph of the distribution of their 2018 salaries. Based on this graph, we expect the mean salary to be

Some individuals are carriers of the bacterium Streptococcus pyogenes. Investigators examined 1398 schoolchildren to determine if they were carriers or not, and noted the size of their tonsils.  Here are the results: Tonsil Size normal large very large Total Carrier 19 29 24 72 Non-carrier 497 560 269 1326 Total 516 589 293 1398  Which of the following hypotheses should be used to test if the relationship between carrier status and tonsil size is statistically significant?

A quality improvement team at a clinic randomly selected 11 patients and recorded their wait times after implementing a new check-in system. Before the new check-in system, the mean wait time was 22 minutes, and the standard deviation was 8 minutes.  Here are the measurements for the wait times from the sample:       10,    15,   20,   17,   30,   25,   15,   12,   12,   15,   17 The type of graph being used to display wait times is called a [a]. The shape of the distribution of wait times is [b]. The team conducting the study want to estimate the mean wait time using the new check-in system using these 11 randomly selected wait times.  To do so, they should use a(n) [c].

A brewing company employee was interested how to improve corn yields.  There is reason to suspect that drying the seeds in a kiln before planting them might improve yield.  The employee had access to 9 small plots of land.  Because soil fertility might vary from plot to plot, he divided each plot in half and planted regular seed in one half and kiln-dried seed in the other (randomly deciding which kind of seed was planted in each half plot).  Following are the resulting data (yield is measured in pounds per acre). What experimental design is this? [design] The appropriate hypothesis test was performed on the above data and resulted in a p-value of 0.0704.  Using the 0.05 level of significance, the correct conclusion is [conclusion]. Plot Kiln-dried seed Regular seed Difference in yield 1 2009 1903 106 2 1915 1935 – 20 3 2011 1910 101 4 2463 2496 – 33 5 2122 2060 62 6 1482 1444 38 7 1542 1612 – 70 8 1443 1316 127 9 1535 1511 24  

Researchers took a random sample of 64 truck drivers and reported that they averaged 2,920 miles per week with a standard deviation of 72 miles.  What is the standard error of the sample mean? (Round your answer to the nearest whole number.)

For an exit poll of a recent ballot issue as to whether a county tax should be imposed to fund public transportation, 53.1% of those polled said ‘yes.’  Which of the following statistical inference procedures should be used to determine if the majority of the population approved of the tax?

Food additives, such as the plant-based extract tara gum, are used in industrial fool preparations as thickening agents to stabilize emulsions and create an impression of thickness and creaminess without adding extra calories.  The effect of tara gum on the viscosity (in millipascal-seconds, mPa.s) of fruit yogurt drinks was assessed for various concentrations of tara gum (in grams per 100 grams of drink, g/100g).  The findings are summarized in the following scatterplot. The relationship between the viscosity of the yogurt drink and concentration of the tara gum can be described as [a]. Which one of the following is the best guessed value of the correlation coefficient for the viscosity of the yogurt drink and concentration of the tara gum? [b]

Flight crews are exposed to more cosmic radiation than most people because of the time spent at high altitudes.  Fifty crew members of Xinjiang Airlines wore radiation detectors.  Investigators reported an average exposure of 219 mrems (millirems), with a margin of error of ± 9.7 mrems.  Which of the following is a correct interpretation of this statement?

Flight crews are exposed to more cosmic radiation than most people because of the time spent at high altitudes.  Fifty crew members of Xinjiang Airlines wore radiation detectors.  Investigators reported an average exposure of 219 mrems (millirems), with a margin of error of ± 9.7 mrems.  Which of the following is a correct interpretation of this statement?