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Finding the Fourth Proportional to 753.12, 1,038.29 and 643.77

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Solution

The fourth proportional to 753.12, 1,038.29 and 643.77 is: 887.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    753.12 : 1,038.29 = 643.77 : x
  2. Step 2: Convert to fraction form
    753.12/1,038.29 = 643.77/x
  3. Step 3: Cross multiply
    753.12x = 1,038.29 × 643.77
  4. Step 4: Simplify right side
    753.12x = 668,416.73
  5. Step 5: Solve for x
    x = 668,416.73/753.12
  6. Step 6: Final answer
    x = 887.53

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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.