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Finding the Fourth Proportional to 1,380.75, 1,905.53 and 775.15

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Solution

The fourth proportional to 1,380.75, 1,905.53 and 775.15 is: 1,069.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,380.75 : 1,905.53 = 775.15 : x
  2. Step 2: Convert to fraction form
    1,380.75/1,905.53 = 775.15/x
  3. Step 3: Cross multiply
    1,380.75x = 1,905.53 × 775.15
  4. Step 4: Simplify right side
    1,380.75x = 1,477,062.94
  5. Step 5: Solve for x
    x = 1,477,062.94/1,380.75
  6. Step 6: Final answer
    x = 1,069.75

Related Problems

Find fourth proportional to 690.38, 952.76 and 387.57
Half scale
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Double scale
Find fourth proportional to 1,381.75, 1,906.91 and 776.15
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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.