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Finding the Fourth Proportional to 812.77, 1,121.85 and 665.75

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Solution

The fourth proportional to 812.77, 1,121.85 and 665.75 is: 918.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.77 : 1,121.85 = 665.75 : x
  2. Step 2: Convert to fraction form
    812.77/1,121.85 = 665.75/x
  3. Step 3: Cross multiply
    812.77x = 1,121.85 × 665.75
  4. Step 4: Simplify right side
    812.77x = 746,874.44
  5. Step 5: Solve for x
    x = 746,874.44/812.77
  6. Step 6: Final answer
    x = 918.93

Related Problems

Find fourth proportional to 406.38, 560.93 and 332.88
Half scale
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Double scale
Find fourth proportional to 813.77, 1,123.23 and 666.75
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.