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Finding the Fourth Proportional to 1,190, 1,785 and 420.50

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Solution

The fourth proportional to 1,190, 1,785 and 420.50 is: 630.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,190 : 1,785 = 420.50 : x
  2. Step 2: Convert to fraction form
    1,190/1,785 = 420.50/x
  3. Step 3: Cross multiply
    1,190x = 1,785 × 420.50
  4. Step 4: Simplify right side
    1,190x = 750,592.50
  5. Step 5: Solve for x
    x = 750,592.50/1,190
  6. Step 6: Final answer
    x = 630.75

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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.