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Finding the Fourth Proportional to 525.80, 788.70 and 428.60

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Solution

The fourth proportional to 525.80, 788.70 and 428.60 is: 642.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    525.80 : 788.70 = 428.60 : x
  2. Step 2: Convert to fraction form
    525.80/788.70 = 428.60/x
  3. Step 3: Cross multiply
    525.80x = 788.70 × 428.60
  4. Step 4: Simplify right side
    525.80x = 338,036.82
  5. Step 5: Solve for x
    x = 338,036.82/525.80
  6. Step 6: Final answer
    x = 642.90

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.