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Finding the Fourth Proportional to 429.60, 646.95 and 386.78

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Solution

The fourth proportional to 429.60, 646.95 and 386.78 is: 582.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.60 : 646.95 = 386.78 : x
  2. Step 2: Convert to fraction form
    429.60/646.95 = 386.78/x
  3. Step 3: Cross multiply
    429.60x = 646.95 × 386.78
  4. Step 4: Simplify right side
    429.60x = 250,223.36
  5. Step 5: Solve for x
    x = 250,223.36/429.60
  6. Step 6: Final answer
    x = 582.45

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.