Direct and Inverse Variation

 y varies directly with x, and y is 84 when x is 16. What is the constant of proportionality?

• y = (21/4)x
• k= 21
• k= 5.25
• k= 4/21

The amount of money earned on a job is directly proportional to the number of hours worked.  If $70.00 is earned in 5 hours, how much money is earned in 22 hours of work?

• $2
• $308
• $1.57
• $265

Is the given table a direct variation? If so, what is the constant of proportionality?

• Yes; 1/4
• Yes; 4
• Yes; 1/2
• No

Is this a direct variation?
y=2x

• yes
• no

Does the relationship represent direct variation?

• Yes
• No

Is the given table a direct variation? If so, what is the constant of proportionality?

• Yes; 8
• Yes; 16
• Yes; 24
• No

Trina's paycheck earnings varies directly as the number of hours she works. If she works 19 hours and earns $187.15, what should she earn if she worked 40 hours? 

• $394
• $440
• $472.80
• $512.20

The interest received on a savings account varies directly with the amount deposited. Daniel received $55.35 in interest on $1230 he deposited. How much interest would Daniel have received if he had deposited $2000 into his account?

• 34.04
• 90.00
• 1,285.35
• 44,444.44

What is the constant (k) in this inverse variation?
y = 400/x

• x
• y
• 400
• Not enough information given

Determine the type of variation:

• Direct

• Inverse