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Finding the Fourth Proportional to 1,210.50, 1,670.63 and 686.70

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Solution

The fourth proportional to 1,210.50, 1,670.63 and 686.70 is: 947.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,210.50 : 1,670.63 = 686.70 : x
  2. Step 2: Convert to fraction form
    1,210.50/1,670.63 = 686.70/x
  3. Step 3: Cross multiply
    1,210.50x = 1,670.63 × 686.70
  4. Step 4: Simplify right side
    1,210.50x = 1,147,218.19
  5. Step 5: Solve for x
    x = 1,147,218.19/1,210.50
  6. Step 6: Final answer
    x = 947.72

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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.