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Finding the Fourth Proportional to 870.88, 1,200.66 and 646.09

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Solution

The fourth proportional to 870.88, 1,200.66 and 646.09 is: 890.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.88 : 1,200.66 = 646.09 : x
  2. Step 2: Convert to fraction form
    870.88/1,200.66 = 646.09/x
  3. Step 3: Cross multiply
    870.88x = 1,200.66 × 646.09
  4. Step 4: Simplify right side
    870.88x = 775,734.42
  5. Step 5: Solve for x
    x = 775,734.42/870.88
  6. Step 6: Final answer
    x = 890.75

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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.