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Finding the Fourth Proportional to 643.38, 887.16 and 477.90

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Solution

The fourth proportional to 643.38, 887.16 and 477.90 is: 658.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.38 : 887.16 = 477.90 : x
  2. Step 2: Convert to fraction form
    643.38/887.16 = 477.90/x
  3. Step 3: Cross multiply
    643.38x = 887.16 × 477.90
  4. Step 4: Simplify right side
    643.38x = 423,973.76
  5. Step 5: Solve for x
    x = 423,973.76/643.38
  6. Step 6: Final answer
    x = 658.98

Related Problems

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Half scale
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Double scale
Find fourth proportional to 644.38, 888.54 and 478.90
Similar ratio
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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.