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Finding the Fourth Proportional to 855.90, 1,283.58 and 509.40

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Solution

The fourth proportional to 855.90, 1,283.58 and 509.40 is: 763.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    855.90 : 1,283.58 = 509.40 : x
  2. Step 2: Convert to fraction form
    855.90/1,283.58 = 509.40/x
  3. Step 3: Cross multiply
    855.90x = 1,283.58 × 509.40
  4. Step 4: Simplify right side
    855.90x = 653,855.65
  5. Step 5: Solve for x
    x = 653,855.65/855.90
  6. Step 6: Final answer
    x = 763.94

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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.