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Finding the Fourth Proportional to 917.28, 1,378 and 880.40

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Solution

The fourth proportional to 917.28, 1,378 and 880.40 is: 1,322.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    917.28 : 1,378 = 880.40 : x
  2. Step 2: Convert to fraction form
    917.28/1,378 = 880.40/x
  3. Step 3: Cross multiply
    917.28x = 1,378 × 880.40
  4. Step 4: Simplify right side
    917.28x = 1,213,191.20
  5. Step 5: Solve for x
    x = 1,213,191.20/917.28
  6. Step 6: Final answer
    x = 1,322.60

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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.