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Finding the Fourth Proportional to 260.40, 390.70 and 256.30

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Solution

The fourth proportional to 260.40, 390.70 and 256.30 is: 384.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    260.40 : 390.70 = 256.30 : x
  2. Step 2: Convert to fraction form
    260.40/390.70 = 256.30/x
  3. Step 3: Cross multiply
    260.40x = 390.70 × 256.30
  4. Step 4: Simplify right side
    260.40x = 100,136.41
  5. Step 5: Solve for x
    x = 100,136.41/260.40
  6. Step 6: Final answer
    x = 384.55

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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.