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Finding the Fourth Proportional to 419.76, 579.40 and 288.76

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Solution

The fourth proportional to 419.76, 579.40 and 288.76 is: 398.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.76 : 579.40 = 288.76 : x
  2. Step 2: Convert to fraction form
    419.76/579.40 = 288.76/x
  3. Step 3: Cross multiply
    419.76x = 579.40 × 288.76
  4. Step 4: Simplify right side
    419.76x = 167,307.54
  5. Step 5: Solve for x
    x = 167,307.54/419.76
  6. Step 6: Final answer
    x = 398.58

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.