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Finding the Fourth Proportional to 756.19, 1,042.90 and 638.74

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Solution

The fourth proportional to 756.19, 1,042.90 and 638.74 is: 880.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    756.19 : 1,042.90 = 638.74 : x
  2. Step 2: Convert to fraction form
    756.19/1,042.90 = 638.74/x
  3. Step 3: Cross multiply
    756.19x = 1,042.90 × 638.74
  4. Step 4: Simplify right side
    756.19x = 666,141.95
  5. Step 5: Solve for x
    x = 666,141.95/756.19
  6. Step 6: Final answer
    x = 880.92

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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.