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Finding the Fourth Proportional to 740.89, 1,111.88 and 278.78

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Solution

The fourth proportional to 740.89, 1,111.88 and 278.78 is: 418.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    740.89 : 1,111.88 = 278.78 : x
  2. Step 2: Convert to fraction form
    740.89/1,111.88 = 278.78/x
  3. Step 3: Cross multiply
    740.89x = 1,111.88 × 278.78
  4. Step 4: Simplify right side
    740.89x = 309,969.91
  5. Step 5: Solve for x
    x = 309,969.91/740.89
  6. Step 6: Final answer
    x = 418.38

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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.