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Finding the Fourth Proportional to 1,870.60, 2,805.90 and 1,287.40

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Solution

The fourth proportional to 1,870.60, 2,805.90 and 1,287.40 is: 1,931.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,870.60 : 2,805.90 = 1,287.40 : x
  2. Step 2: Convert to fraction form
    1,870.60/2,805.90 = 1,287.40/x
  3. Step 3: Cross multiply
    1,870.60x = 2,805.90 × 1,287.40
  4. Step 4: Simplify right side
    1,870.60x = 3,612,315.66
  5. Step 5: Solve for x
    x = 3,612,315.66/1,870.60
  6. Step 6: Final answer
    x = 1,931.10

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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.