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Finding the Fourth Proportional to 642.84, 885.66 and 612.12

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Solution

The fourth proportional to 642.84, 885.66 and 612.12 is: 843.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.84 : 885.66 = 612.12 : x
  2. Step 2: Convert to fraction form
    642.84/885.66 = 612.12/x
  3. Step 3: Cross multiply
    642.84x = 885.66 × 612.12
  4. Step 4: Simplify right side
    642.84x = 542,130.20
  5. Step 5: Solve for x
    x = 542,130.20/642.84
  6. Step 6: Final answer
    x = 843.34

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.