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Finding the Fourth Proportional to 858.77, 1,288.37 and 420.26

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Solution

The fourth proportional to 858.77, 1,288.37 and 420.26 is: 630.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.77 : 1,288.37 = 420.26 : x
  2. Step 2: Convert to fraction form
    858.77/1,288.37 = 420.26/x
  3. Step 3: Cross multiply
    858.77x = 1,288.37 × 420.26
  4. Step 4: Simplify right side
    858.77x = 541,444.98
  5. Step 5: Solve for x
    x = 541,444.98/858.77
  6. Step 6: Final answer
    x = 630.49

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1.5x scale

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.