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Finding the Fourth Proportional to 643.64, 887.76 and 407.32

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Solution

The fourth proportional to 643.64, 887.76 and 407.32 is: 561.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.64 : 887.76 = 407.32 : x
  2. Step 2: Convert to fraction form
    643.64/887.76 = 407.32/x
  3. Step 3: Cross multiply
    643.64x = 887.76 × 407.32
  4. Step 4: Simplify right side
    643.64x = 361,602.40
  5. Step 5: Solve for x
    x = 361,602.40/643.64
  6. Step 6: Final answer
    x = 561.81

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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.