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Finding the Fourth Proportional to 711.90, 981.32 and 561.51

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Solution

The fourth proportional to 711.90, 981.32 and 561.51 is: 774.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    711.90 : 981.32 = 561.51 : x
  2. Step 2: Convert to fraction form
    711.90/981.32 = 561.51/x
  3. Step 3: Cross multiply
    711.90x = 981.32 × 561.51
  4. Step 4: Simplify right side
    711.90x = 551,018.19
  5. Step 5: Solve for x
    x = 551,018.19/711.90
  6. Step 6: Final answer
    x = 774.01

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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.