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Finding the Fourth Proportional to 817.19, 1,127.69 and 485.42

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Solution

The fourth proportional to 817.19, 1,127.69 and 485.42 is: 669.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.19 : 1,127.69 = 485.42 : x
  2. Step 2: Convert to fraction form
    817.19/1,127.69 = 485.42/x
  3. Step 3: Cross multiply
    817.19x = 1,127.69 × 485.42
  4. Step 4: Simplify right side
    817.19x = 547,403.28
  5. Step 5: Solve for x
    x = 547,403.28/817.19
  6. Step 6: Final answer
    x = 669.86

Related Problems

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Half scale
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Double scale
Find fourth proportional to 818.19, 1,129.07 and 486.42
Similar ratio
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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.