Home / 1,209.20-1,666.32-928.40

Finding the Fourth Proportional to 1,209.20, 1,666.32 and 928.40

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Solution

The fourth proportional to 1,209.20, 1,666.32 and 928.40 is: 1,279.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,209.20 : 1,666.32 = 928.40 : x
  2. Step 2: Convert to fraction form
    1,209.20/1,666.32 = 928.40/x
  3. Step 3: Cross multiply
    1,209.20x = 1,666.32 × 928.40
  4. Step 4: Simplify right side
    1,209.20x = 1,547,011.49
  5. Step 5: Solve for x
    x = 1,547,011.49/1,209.20
  6. Step 6: Final answer
    x = 1,279.37

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.