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Finding the Fourth Proportional to 388.40, 536.43 and 257.99

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Solution

The fourth proportional to 388.40, 536.43 and 257.99 is: 356.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.40 : 536.43 = 257.99 : x
  2. Step 2: Convert to fraction form
    388.40/536.43 = 257.99/x
  3. Step 3: Cross multiply
    388.40x = 536.43 × 257.99
  4. Step 4: Simplify right side
    388.40x = 138,393.58
  5. Step 5: Solve for x
    x = 138,393.58/388.40
  6. Step 6: Final answer
    x = 356.32

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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.