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Finding the Fourth Proportional to 931.90, 1,286.10 and 558.90

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Solution

The fourth proportional to 931.90, 1,286.10 and 558.90 is: 771.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    931.90 : 1,286.10 = 558.90 : x
  2. Step 2: Convert to fraction form
    931.90/1,286.10 = 558.90/x
  3. Step 3: Cross multiply
    931.90x = 1,286.10 × 558.90
  4. Step 4: Simplify right side
    931.90x = 718,792.07
  5. Step 5: Solve for x
    x = 718,792.07/931.90
  6. Step 6: Final answer
    x = 771.32

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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.