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Finding the Fourth Proportional to 790.78, 1,185.28 and 270.30

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Solution

The fourth proportional to 790.78, 1,185.28 and 270.30 is: 405.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    790.78 : 1,185.28 = 270.30 : x
  2. Step 2: Convert to fraction form
    790.78/1,185.28 = 270.30/x
  3. Step 3: Cross multiply
    790.78x = 1,185.28 × 270.30
  4. Step 4: Simplify right side
    790.78x = 320,381.18
  5. Step 5: Solve for x
    x = 320,381.18/790.78
  6. Step 6: Final answer
    x = 405.15

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Double scale
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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.