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Finding the Fourth Proportional to 678.95, 936.95 and 384.20

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Solution

The fourth proportional to 678.95, 936.95 and 384.20 is: 530.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.95 : 936.95 = 384.20 : x
  2. Step 2: Convert to fraction form
    678.95/936.95 = 384.20/x
  3. Step 3: Cross multiply
    678.95x = 936.95 × 384.20
  4. Step 4: Simplify right side
    678.95x = 359,976.19
  5. Step 5: Solve for x
    x = 359,976.19/678.95
  6. Step 6: Final answer
    x = 530.20

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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.