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Finding the Fourth Proportional to 280, 386.40 and 188

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Solution

The fourth proportional to 280, 386.40 and 188 is: 259.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    280 : 386.40 = 188 : x
  2. Step 2: Convert to fraction form
    280/386.40 = 188/x
  3. Step 3: Cross multiply
    280x = 386.40 × 188
  4. Step 4: Simplify right side
    280x = 72,643.20
  5. Step 5: Solve for x
    x = 72,643.20/280
  6. Step 6: Final answer
    x = 259.44

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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.