Home / 1,212.11-1,818.10-390.36

Finding the Fourth Proportional to 1,212.11, 1,818.10 and 390.36

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Solution

The fourth proportional to 1,212.11, 1,818.10 and 390.36 is: 585.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,212.11 : 1,818.10 = 390.36 : x
  2. Step 2: Convert to fraction form
    1,212.11/1,818.10 = 390.36/x
  3. Step 3: Cross multiply
    1,212.11x = 1,818.10 × 390.36
  4. Step 4: Simplify right side
    1,212.11x = 709,719.04
  5. Step 5: Solve for x
    x = 709,719.04/1,212.11
  6. Step 6: Final answer
    x = 585.52

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Double scale
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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.