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Finding the Fourth Proportional to 861.05, 1,290.76 and 374.45

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Solution

The fourth proportional to 861.05, 1,290.76 and 374.45 is: 561.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    861.05 : 1,290.76 = 374.45 : x
  2. Step 2: Convert to fraction form
    861.05/1,290.76 = 374.45/x
  3. Step 3: Cross multiply
    861.05x = 1,290.76 × 374.45
  4. Step 4: Simplify right side
    861.05x = 483,317.69
  5. Step 5: Solve for x
    x = 483,317.69/861.05
  6. Step 6: Final answer
    x = 561.31

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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.