Home / 669.80-1,004.70-612.20

Finding the Fourth Proportional to 669.80, 1,004.70 and 612.20

Calculator

Solution

The fourth proportional to 669.80, 1,004.70 and 612.20 is: 918.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.80 : 1,004.70 = 612.20 : x
  2. Step 2: Convert to fraction form
    669.80/1,004.70 = 612.20/x
  3. Step 3: Cross multiply
    669.80x = 1,004.70 × 612.20
  4. Step 4: Simplify right side
    669.80x = 615,077.34
  5. Step 5: Solve for x
    x = 615,077.34/669.80
  6. Step 6: Final answer
    x = 918.30

Related Problems

Find fourth proportional to 334.90, 502.35 and 306.10
Half scale
Find fourth proportional to 1,339.60, 2,009.40 and 1,224.40
Double scale
Find fourth proportional to 670.80, 1,006.20 and 613.20
Similar ratio
Find fourth proportional to 1,004.70, 1,507.05 and 918.30
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.