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Finding the Fourth Proportional to 839.70, 1,158.10 and 783.81

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Solution

The fourth proportional to 839.70, 1,158.10 and 783.81 is: 1,081.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.70 : 1,158.10 = 783.81 : x
  2. Step 2: Convert to fraction form
    839.70/1,158.10 = 783.81/x
  3. Step 3: Cross multiply
    839.70x = 1,158.10 × 783.81
  4. Step 4: Simplify right side
    839.70x = 907,728.40
  5. Step 5: Solve for x
    x = 907,728.40/839.70
  6. Step 6: Final answer
    x = 1,081.02

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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.