Exam 1: Linear Equations and Graphs

Use the REGRESSION feature on a graphing calculator. -Efficiency experts rate employees according to job performance and attitude.The results for several randomly selected employees are given below. Find the regression line which can be used to predict performance rating if attitude rating is known.

Provide an appropriate response. -Write the equation of a line that passes through (-1,4)and (5,-1).Write the final answer in the form Ax + By = C where A,B,and C are integers with no common divisors (other than ±1)and A > 0.

Write the slope-intercept equation (y = mx + b) for a line with the given characteristics. -m = 3,passing through (1,-2)

Use the graph to find the average rate of change. -

Solve the problem. -A small company that makes hand-sewn leather shoes has fixed costs of $320 a day,and total costs of $1200 per day at an output of 20 pairs of shoes per day.Assume that total cost C is linearly related to output x.Find an equation of the line relating output to cost.Write the final answer in the form C = mx + b.

Choose the one alternative that best completes the statement or answers the question.Solve the problem. Express your answer as an integer or simplified fraction. -

Determine whether the slope of the line is positive, negative, zero, or undefined. -

Find the slope and y intercept of the graph of the equation. -y=

Write the slope-intercept equation (y = mx + b) for a line with the given characteristics. -m = - 4,y-intercept (0,-7)

Write an equation of the line with the indicated slope and y intercept. -Slope = -4,y intercept = 6

Provide an appropriate response. -Given two points (x1,y1)and (x2,y2),the ratio of the change in y to the change in x is called.

Provide an appropriate response. -Find the line passing through the two points.Write the equation in standard form.(10,9)and (10,1)

Graph the linear equation and determine its slope, if it exists. -2x - 5y = 20

Use the REGRESSION feature on a graphing calculator. -For some reason the quality of production decreased as the year progressed at a flash drive manufacturing plant.The following data represent the percentage of defective flash drives produced at the plant in the corresponding month of the year. Use the regression equation with values rounded to four decimals to predict the percentage of defective drives in month 6,June.

Write an equation of the line with the indicated slope and y intercept. -Slope = 4,y intercept = -5

Graph the linear equation and determine its slope, if it exists. -3x + 5y = 11

Solve the problem. -You have $50,000 and wish to invest part at 10% and the rest at 6%.How much should be invested at each rate to produce the same return as if it all had been invested at 9%?

Find the slope and y intercept of the graph of the equation. -y = x - 5

Use the REGRESSION feature on a graphing calculator. -A study was conducted to compare the average time spent in the lab each week versus course grade for computer students.The results are recorded in the table below. Use linear regression to find a linear function that predicts a student's course grade as a function of the number of hours spent in lab.

Solve the problem. -The cost for labor associated with fixing a washing machine is computed as follows: There is a fixed charge of $25 for the repairman to come to the house,to which a charge of $20 per hour is added.Find an equation that Can be used to determine the labor cost,C,of a repair that takes x hours.Write the final answer in the form C = Mx + b.