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Finding the Fourth Proportional to 810.15, 1,214.90 and 347.69

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Solution

The fourth proportional to 810.15, 1,214.90 and 347.69 is: 521.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.15 : 1,214.90 = 347.69 : x
  2. Step 2: Convert to fraction form
    810.15/1,214.90 = 347.69/x
  3. Step 3: Cross multiply
    810.15x = 1,214.90 × 347.69
  4. Step 4: Simplify right side
    810.15x = 422,411.18
  5. Step 5: Solve for x
    x = 422,411.18/810.15
  6. Step 6: Final answer
    x = 521.40

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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.