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Finding the Fourth Proportional to 630.98, 870.64 and 421.39

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Solution

The fourth proportional to 630.98, 870.64 and 421.39 is: 581.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    630.98 : 870.64 = 421.39 : x
  2. Step 2: Convert to fraction form
    630.98/870.64 = 421.39/x
  3. Step 3: Cross multiply
    630.98x = 870.64 × 421.39
  4. Step 4: Simplify right side
    630.98x = 366,878.99
  5. Step 5: Solve for x
    x = 366,878.99/630.98
  6. Step 6: Final answer
    x = 581.44

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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.