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Finding the Fourth Proportional to 841.21, 1,261.18 and 430

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Solution

The fourth proportional to 841.21, 1,261.18 and 430 is: 644.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    841.21 : 1,261.18 = 430 : x
  2. Step 2: Convert to fraction form
    841.21/1,261.18 = 430/x
  3. Step 3: Cross multiply
    841.21x = 1,261.18 × 430
  4. Step 4: Simplify right side
    841.21x = 542,307.40
  5. Step 5: Solve for x
    x = 542,307.40/841.21
  6. Step 6: Final answer
    x = 644.68

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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.