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Finding the Fourth Proportional to 1,878.40, 2,817.60 and 491.78

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Solution

The fourth proportional to 1,878.40, 2,817.60 and 491.78 is: 737.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,878.40 : 2,817.60 = 491.78 : x
  2. Step 2: Convert to fraction form
    1,878.40/2,817.60 = 491.78/x
  3. Step 3: Cross multiply
    1,878.40x = 2,817.60 × 491.78
  4. Step 4: Simplify right side
    1,878.40x = 1,385,639.33
  5. Step 5: Solve for x
    x = 1,385,639.33/1,878.40
  6. Step 6: Final answer
    x = 737.67

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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.