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Finding the Fourth Proportional to 645, 889.50 and 497.40

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Solution

The fourth proportional to 645, 889.50 and 497.40 is: 685.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    645 : 889.50 = 497.40 : x
  2. Step 2: Convert to fraction form
    645/889.50 = 497.40/x
  3. Step 3: Cross multiply
    645x = 889.50 × 497.40
  4. Step 4: Simplify right side
    645x = 442,437.30
  5. Step 5: Solve for x
    x = 442,437.30/645
  6. Step 6: Final answer
    x = 685.95

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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.