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Finding the Fourth Proportional to 765.68, 1,148.16 and 278.40

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Solution

The fourth proportional to 765.68, 1,148.16 and 278.40 is: 417.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.68 : 1,148.16 = 278.40 : x
  2. Step 2: Convert to fraction form
    765.68/1,148.16 = 278.40/x
  3. Step 3: Cross multiply
    765.68x = 1,148.16 × 278.40
  4. Step 4: Simplify right side
    765.68x = 319,647.74
  5. Step 5: Solve for x
    x = 319,647.74/765.68
  6. Step 6: Final answer
    x = 417.47

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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.