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Finding the Fourth Proportional to 1,138.07, 1,570.51 and 640.75

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Solution

The fourth proportional to 1,138.07, 1,570.51 and 640.75 is: 884.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,138.07 : 1,570.51 = 640.75 : x
  2. Step 2: Convert to fraction form
    1,138.07/1,570.51 = 640.75/x
  3. Step 3: Cross multiply
    1,138.07x = 1,570.51 × 640.75
  4. Step 4: Simplify right side
    1,138.07x = 1,006,304.28
  5. Step 5: Solve for x
    x = 1,006,304.28/1,138.07
  6. Step 6: Final answer
    x = 884.22

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1.5x scale

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.