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Finding the Fourth Proportional to 858.87, 1,185.08 and 485.71

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Solution

The fourth proportional to 858.87, 1,185.08 and 485.71 is: 670.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.87 : 1,185.08 = 485.71 : x
  2. Step 2: Convert to fraction form
    858.87/1,185.08 = 485.71/x
  3. Step 3: Cross multiply
    858.87x = 1,185.08 × 485.71
  4. Step 4: Simplify right side
    858.87x = 575,599.82
  5. Step 5: Solve for x
    x = 575,599.82/858.87
  6. Step 6: Final answer
    x = 670.18

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1.5x scale

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.