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Finding the Fourth Proportional to 821.24, 1,130.40 and 812.12

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Solution

The fourth proportional to 821.24, 1,130.40 and 812.12 is: 1,117.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.24 : 1,130.40 = 812.12 : x
  2. Step 2: Convert to fraction form
    821.24/1,130.40 = 812.12/x
  3. Step 3: Cross multiply
    821.24x = 1,130.40 × 812.12
  4. Step 4: Simplify right side
    821.24x = 918,020.45
  5. Step 5: Solve for x
    x = 918,020.45/821.24
  6. Step 6: Final answer
    x = 1,117.85

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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.