Exam 1: Discretionary Expenses

The equation of the linear regression line of the scatterplot defined by these points: (1,45), (2,35), (3,20), (4,5)is y = -13.5x + 60.

Calvin is graduating and wants to get a job in a government agency.He has done some research and will interview with two different agencies.The first agency offers starting salaries with a mean of $47,000 and a standard deviation of $1,500.The second agency's average starting salary is also $47,000,with a standard deviation of $4,000.With which agency is Calvin more likely to start with an offer of $1,000 per week or more?

Catalina's mother recorded her height each year.The table below shows her height,in inches. ​ Find the equation of the regression line.

What is the most commonly used measure of dispersion?

The Learners just got a notification about their past 4 months of gas and electric bills stating that the average for the winter months was $393.46.Mr.Learner remembered that it was cold in January,but was unable to find his bill for that month.Using what you know about measures of central tendency,help Mr.Learner calculate what his January gas and electric bill must have been.

Sarah is a server at a restaurant and has been keeping track of the tips she receives.The smallest bill she received a tip for was $24.44,and the largest bill was $89.75.She used linear regression to model tips received (y)as a function of the restaurant bill (x).Using her data,she wrote a linear regression equation of y = 0.22x-0.27.Sarah would really like to get a $50 tip.Based on her linear regression equation,what would the restaurant bill have to be to lead to a $50 tip? Would this calculation be considered interpolation or extrapolation?

Does the graph below have a positive,a negative,or no correlation? ​

Rebecca will be entering college next fall and is trying to decide how much to spend on a laptop.After researching models online,she has found several that would meet her needs.Their costs are: $979;$1,349;$1,279;$1,349;$1,899;$2,049;$875;and $1,099.She determined the median to be $1,359.

What kind of data does a scatterplot use?

Pamela called nine repair shops for quotes for auto repairs and pick the quote closest to the mean.The prices are $139,$150,$345,$99,$169,$155,$140,$200,and $160.She heard that data collections that are normally distributed will have 95% of its values within 2 standard deviations of the mean and wants to remove any quotes outside of that mark before determining a revised average that will help her make a decision.What is the mean price quote for 95% of the auto repairs that are within 2 standard deviations of the mean?

What is the standard deviation for the following frequency distribution? ​ ​

Which column in a frequency distribution table is an indicator of which percentile each of the possible values falls in?

The mean for Mr.Foster's Financial Algebra test was 70,and the standard deviation was 4.2.Ms.Helmer's mean for her test was 35,and the standard deviation was 5.7.Two friends were arguing about which did better on the test.Becky got a 78 on Mr.Foster's test,whereas Erin got a 45 on Ms.Helmer's test.Help settle the argument.

Stephen is starting a wine cellar but only wants to stock bottles in the top 10% of Wine magazine's ratings of 500 wines.The average rating given by the magazine was 72 with a standard deviation of 7.1.Use the standard distribution table to help Stephen discover what wine rating is necessary for a wine to be in the top 10%.

McKenzie found the correlation coefficient on a set of data to be -0.20.Which term best describes the correlation?