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Finding the Fourth Proportional to 287.69, 428.74 and 278.46

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Solution

The fourth proportional to 287.69, 428.74 and 278.46 is: 414.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.69 : 428.74 = 278.46 : x
  2. Step 2: Convert to fraction form
    287.69/428.74 = 278.46/x
  3. Step 3: Cross multiply
    287.69x = 428.74 × 278.46
  4. Step 4: Simplify right side
    287.69x = 119,386.24
  5. Step 5: Solve for x
    x = 119,386.24/287.69
  6. Step 6: Final answer
    x = 414.99

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.