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Finding the Fourth Proportional to 920.32, 1,269.76 and 643.84

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Solution

The fourth proportional to 920.32, 1,269.76 and 643.84 is: 888.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.32 : 1,269.76 = 643.84 : x
  2. Step 2: Convert to fraction form
    920.32/1,269.76 = 643.84/x
  3. Step 3: Cross multiply
    920.32x = 1,269.76 × 643.84
  4. Step 4: Simplify right side
    920.32x = 817,522.28
  5. Step 5: Solve for x
    x = 817,522.28/920.32
  6. Step 6: Final answer
    x = 888.30

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.