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Finding the Fourth Proportional to 987.44, 1,479.80 and 770

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Solution

The fourth proportional to 987.44, 1,479.80 and 770 is: 1,153.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    987.44 : 1,479.80 = 770 : x
  2. Step 2: Convert to fraction form
    987.44/1,479.80 = 770/x
  3. Step 3: Cross multiply
    987.44x = 1,479.80 × 770
  4. Step 4: Simplify right side
    987.44x = 1,139,446
  5. Step 5: Solve for x
    x = 1,139,446/987.44
  6. Step 6: Final answer
    x = 1,153.94

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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.