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Finding the Fourth Proportional to 359.40, 538.74 and 128.15

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Solution

The fourth proportional to 359.40, 538.74 and 128.15 is: 192.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    359.40 : 538.74 = 128.15 : x
  2. Step 2: Convert to fraction form
    359.40/538.74 = 128.15/x
  3. Step 3: Cross multiply
    359.40x = 538.74 × 128.15
  4. Step 4: Simplify right side
    359.40x = 69,036.84
  5. Step 5: Solve for x
    x = 69,036.84/359.40
  6. Step 6: Final answer
    x = 192.09

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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.