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Finding the Fourth Proportional to 909.51, 1,254.19 and 643.83

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Solution

The fourth proportional to 909.51, 1,254.19 and 643.83 is: 887.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    909.51 : 1,254.19 = 643.83 : x
  2. Step 2: Convert to fraction form
    909.51/1,254.19 = 643.83/x
  3. Step 3: Cross multiply
    909.51x = 1,254.19 × 643.83
  4. Step 4: Simplify right side
    909.51x = 807,485.15
  5. Step 5: Solve for x
    x = 807,485.15/909.51
  6. Step 6: Final answer
    x = 887.82

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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.