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Finding the Fourth Proportional to 816.76, 1,224.56 and 420.47

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Solution

The fourth proportional to 816.76, 1,224.56 and 420.47 is: 630.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    816.76 : 1,224.56 = 420.47 : x
  2. Step 2: Convert to fraction form
    816.76/1,224.56 = 420.47/x
  3. Step 3: Cross multiply
    816.76x = 1,224.56 × 420.47
  4. Step 4: Simplify right side
    816.76x = 514,890.74
  5. Step 5: Solve for x
    x = 514,890.74/816.76
  6. Step 6: Final answer
    x = 630.41

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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.