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Finding the Fourth Proportional to 388.40, 535.80 and 290

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Solution

The fourth proportional to 388.40, 535.80 and 290 is: 400.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.40 : 535.80 = 290 : x
  2. Step 2: Convert to fraction form
    388.40/535.80 = 290/x
  3. Step 3: Cross multiply
    388.40x = 535.80 × 290
  4. Step 4: Simplify right side
    388.40x = 155,382
  5. Step 5: Solve for x
    x = 155,382/388.40
  6. Step 6: Final answer
    x = 400.06

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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.