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Finding the Fourth Proportional to 708.68, 977.90 and 398.18

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Solution

The fourth proportional to 708.68, 977.90 and 398.18 is: 549.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    708.68 : 977.90 = 398.18 : x
  2. Step 2: Convert to fraction form
    708.68/977.90 = 398.18/x
  3. Step 3: Cross multiply
    708.68x = 977.90 × 398.18
  4. Step 4: Simplify right side
    708.68x = 389,380.22
  5. Step 5: Solve for x
    x = 389,380.22/708.68
  6. Step 6: Final answer
    x = 549.44

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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.