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For the problems below, define variables and set up the system of equations. Do not solve the system. a) I have 30 coins in my car. The coins are quarters, dimes, and nickels. The total value of the coins is $3.00. The number of quarters is twice the number of dimes. How many of each coin do I have? b) A factory has 1950 machine hours available each week in the cutting department, 1490 hours in the assembly department, and 2160 hours in the finishing department. A chair requires 0.2 hours of cutting, 0.3 hours of assembly, and 0.1 hours of finishing. A cabinet requires 0.5 hours of cutting, 0.4 hours of assembly, and 0.6 hours of finishing. A buffet requires 0.3 hours of cutting, 0.1 hours of assembly, and 0.4 hours of finishing. How many chairs, cabinets, and buffets should be produced in order to use all production capacity?  

When using midterm exam scores to predict a student’s final grade in a class, the student would prefer to have a 

  a. What is the response variable?b. What is the correlation coefficient r?c. Explain in context what the slope of the line means.d. Explain in context what R2 = 98.8% means. 

Administrators of the fire department are concerned about the possibility of implementing a new property tax to raise moneys needed to replace old equipment. They decide to check on public opinion by having a random sample of the city’s population.a. Several plans for choosing the sample are proposed. Write the letter corresponding to the samplingstrategy in the blank next to each plan. 

The correlation coefficient between the hours that a person is awake during a 24-hour period and the hours that same person is asleep during a 24-hour period is most likely to be 

A regression analysis of students’ college grade point averages (GPAs) and their high school GPAs found R2 = 0.311. Which of these is true?I. High school GPA accounts for 31.1% of college GPA.II. 31.1% of college GPAs can be correctly predicted with this model.III. 31.1% of the variance in college GPA can be accounted for by the model 

A researcher wants to compare the performance of three types of pain relievers in volunteers suffering from arthritis. Because people of different ages may suffer arthritis of varying degrees of severity, the subjects are split into two groups: under 60 and over 60. Subjects in each group are randomly assigned to take one of the medications. Twenty minutes later they rate their levels of pain. This experiment … 

Of A-D, which is not a critical part of designing a good experiment?

The model  can be used to predict the stopping distance (in feet) for a car traveling at a specific speed (in mph). According to this model, about how much distance will a car going 65 mph need to stop? 

In an experiment the primary purpose of blinding is to reduce …