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Finding the Fourth Proportional to 838.72, 1,156.08 and 688.78

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Solution

The fourth proportional to 838.72, 1,156.08 and 688.78 is: 949.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.72 : 1,156.08 = 688.78 : x
  2. Step 2: Convert to fraction form
    838.72/1,156.08 = 688.78/x
  3. Step 3: Cross multiply
    838.72x = 1,156.08 × 688.78
  4. Step 4: Simplify right side
    838.72x = 796,284.78
  5. Step 5: Solve for x
    x = 796,284.78/838.72
  6. Step 6: Final answer
    x = 949.40

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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.