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Finding the Fourth Proportional to 839.29, 1,158.40 and 485.45

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Solution

The fourth proportional to 839.29, 1,158.40 and 485.45 is: 670.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.29 : 1,158.40 = 485.45 : x
  2. Step 2: Convert to fraction form
    839.29/1,158.40 = 485.45/x
  3. Step 3: Cross multiply
    839.29x = 1,158.40 × 485.45
  4. Step 4: Simplify right side
    839.29x = 562,345.28
  5. Step 5: Solve for x
    x = 562,345.28/839.29
  6. Step 6: Final answer
    x = 670.02

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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.