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Finding the Fourth Proportional to 1,008.40, 1,510.38 and 642.28

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Solution

The fourth proportional to 1,008.40, 1,510.38 and 642.28 is: 962.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,008.40 : 1,510.38 = 642.28 : x
  2. Step 2: Convert to fraction form
    1,008.40/1,510.38 = 642.28/x
  3. Step 3: Cross multiply
    1,008.40x = 1,510.38 × 642.28
  4. Step 4: Simplify right side
    1,008.40x = 970,086.87
  5. Step 5: Solve for x
    x = 970,086.87/1,008.40
  6. Step 6: Final answer
    x = 962.01

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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.