Proportional Relationships — Quiz Answers

A veterinarian knows that a 50-pound dog gets 0.5 milligram of a certain medicine, and that the number of milligrams, m, varies directly with the weight of the dog, w. The vet uses these steps to find the amount of medicine to give a 10-pound dog. Veterinarian's Work Step 1 Find the constant of variation. k is equal to 0 point 5 over 50 is equal to 0 point 0 1 Step 2 Write the direct variation equation. m is equal to 0 point 0 1 w Step 3 Substitute 10 into the equation to find the dosage for a 10 -pound dog. 10 is equal to 0 point 0 1 w Step 4 Solve for w 10 is equal to 0 point 0 1 w w is equal to 1000 The 10 -pound dog needs 1000 milligrams. In which step did the veterinarian make the first error?

A painter made the given table to show the amount of paint it takes to cover a certain amount of square feet. The amount of paint varies directly with the area of each wall. Amount of Paint and Size of Wall Area of wall open paren ft squared close paren , x 64 144 400 Amount of paint (pints), y 4 9 25 How much paint should the painter expect to use to paint a wall with an area of 256 square feet?

Corrine wrote temperatures in degrees Celsius and the equivalent temperatures in degrees Fahrenheit. Equivalent Temperatures Celsius negative 10 5 10 20 Fahrenheit 14 41 50 68 Which explains how Corrine could determine if the temperatures vary directly?

The given table shows the number of color pages a printer prints out over a period of time. Printed Pages in Color Time (min), x 2 6 8 18 Number of pages, y 3 9 12 27 What is the constant of variation?

Lydia writes the equation with a missing value. y is equal to 5 x minus square She puts a value in the box and says that the equation represents a direct variation. Which explains whether the equation could represent a direct variation?

The length of a spring varies directly with the mass of an object that is attached to it. When a 30 -gram object is attached, the spring stretches 9 centimeters. Which equation relates the mass of the object, m , and the length of the spring, s ?

The given table shows the number of minutes Jalen talks on his mobile phone and the cost of the phone calls. Jalen’s Mobile Phone Cost Number of minutes, x 150 220 250 275 Cost, y 7 point 5 0 dollars 11 point 0 0 dollars 12 point 5 0 dollars 13 point 7 5 dollars If the cost varies directly with the number of minutes Jalen talks on the phone, which equation represents the variation?

Which explains whether or not the values in the table represent a direct variation? x 4 6 10 20 y 1 1 point 5 2 point 5 5

Given that y varies directly with x in the table given, what is the value of y if the value of x is 7? x 2 4 6 10 y 12 24 36 60

The number of milligrams of a certain medicine a veterinarian gives to a dog varies directly with the weight of the dog. If the veterinarian gives a 30 -pound dog 3 fifths milligram of the medicine, which equation relates the weight, w , and the dosage, d ?