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Finding the Fourth Proportional to 841.60, 1,261.92 and 430.40

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Solution

The fourth proportional to 841.60, 1,261.92 and 430.40 is: 645.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    841.60 : 1,261.92 = 430.40 : x
  2. Step 2: Convert to fraction form
    841.60/1,261.92 = 430.40/x
  3. Step 3: Cross multiply
    841.60x = 1,261.92 × 430.40
  4. Step 4: Simplify right side
    841.60x = 543,130.37
  5. Step 5: Solve for x
    x = 543,130.37/841.60
  6. Step 6: Final answer
    x = 645.35

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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.