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Finding the Fourth Proportional to 419.76, 578.70 and 389.16

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Solution

The fourth proportional to 419.76, 578.70 and 389.16 is: 536.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.76 : 578.70 = 389.16 : x
  2. Step 2: Convert to fraction form
    419.76/578.70 = 389.16/x
  3. Step 3: Cross multiply
    419.76x = 578.70 × 389.16
  4. Step 4: Simplify right side
    419.76x = 225,206.89
  5. Step 5: Solve for x
    x = 225,206.89/419.76
  6. Step 6: Final answer
    x = 536.51

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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.