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Finding the Fourth Proportional to 917.28, 1,376.28 and 430.20

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Solution

The fourth proportional to 917.28, 1,376.28 and 430.20 is: 645.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    917.28 : 1,376.28 = 430.20 : x
  2. Step 2: Convert to fraction form
    917.28/1,376.28 = 430.20/x
  3. Step 3: Cross multiply
    917.28x = 1,376.28 × 430.20
  4. Step 4: Simplify right side
    917.28x = 592,075.66
  5. Step 5: Solve for x
    x = 592,075.66/917.28
  6. Step 6: Final answer
    x = 645.47

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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.