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Finding the Fourth Proportional to 975.12, 1,344.60 and 643.56

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Solution

The fourth proportional to 975.12, 1,344.60 and 643.56 is: 887.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    975.12 : 1,344.60 = 643.56 : x
  2. Step 2: Convert to fraction form
    975.12/1,344.60 = 643.56/x
  3. Step 3: Cross multiply
    975.12x = 1,344.60 × 643.56
  4. Step 4: Simplify right side
    975.12x = 865,330.78
  5. Step 5: Solve for x
    x = 865,330.78/975.12
  6. Step 6: Final answer
    x = 887.41

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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.