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Finding the Fourth Proportional to 870.78, 1,201.57 and 637.50

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Solution

The fourth proportional to 870.78, 1,201.57 and 637.50 is: 879.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.78 : 1,201.57 = 637.50 : x
  2. Step 2: Convert to fraction form
    870.78/1,201.57 = 637.50/x
  3. Step 3: Cross multiply
    870.78x = 1,201.57 × 637.50
  4. Step 4: Simplify right side
    870.78x = 766,000.88
  5. Step 5: Solve for x
    x = 766,000.88/870.78
  6. Step 6: Final answer
    x = 879.67

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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.