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Finding the Fourth Proportional to 751.80, 1,128.36 and 405.42

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Solution

The fourth proportional to 751.80, 1,128.36 and 405.42 is: 608.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    751.80 : 1,128.36 = 405.42 : x
  2. Step 2: Convert to fraction form
    751.80/1,128.36 = 405.42/x
  3. Step 3: Cross multiply
    751.80x = 1,128.36 × 405.42
  4. Step 4: Simplify right side
    751.80x = 457,459.71
  5. Step 5: Solve for x
    x = 457,459.71/751.80
  6. Step 6: Final answer
    x = 608.49

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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.