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Finding the Fourth Proportional to 1,871.40, 2,805.74 and 638.12

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Solution

The fourth proportional to 1,871.40, 2,805.74 and 638.12 is: 956.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,871.40 : 2,805.74 = 638.12 : x
  2. Step 2: Convert to fraction form
    1,871.40/2,805.74 = 638.12/x
  3. Step 3: Cross multiply
    1,871.40x = 2,805.74 × 638.12
  4. Step 4: Simplify right side
    1,871.40x = 1,790,398.81
  5. Step 5: Solve for x
    x = 1,790,398.81/1,871.40
  6. Step 6: Final answer
    x = 956.72

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.