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Finding the Fourth Proportional to 686.30, 953.50 and 678.11

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Solution

The fourth proportional to 686.30, 953.50 and 678.11 is: 942.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.30 : 953.50 = 678.11 : x
  2. Step 2: Convert to fraction form
    686.30/953.50 = 678.11/x
  3. Step 3: Cross multiply
    686.30x = 953.50 × 678.11
  4. Step 4: Simplify right side
    686.30x = 646,574.49
  5. Step 5: Solve for x
    x = 646,574.49/686.30
  6. Step 6: Final answer
    x = 942.12

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.