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Finding the Fourth Proportional to 1,000.70, 1,381.40 and 685.87

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Solution

The fourth proportional to 1,000.70, 1,381.40 and 685.87 is: 946.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,000.70 : 1,381.40 = 685.87 : x
  2. Step 2: Convert to fraction form
    1,000.70/1,381.40 = 685.87/x
  3. Step 3: Cross multiply
    1,000.70x = 1,381.40 × 685.87
  4. Step 4: Simplify right side
    1,000.70x = 947,460.37
  5. Step 5: Solve for x
    x = 947,460.37/1,000.70
  6. Step 6: Final answer
    x = 946.79

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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.