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Finding the Fourth Proportional to 660.72, 911.46 and 380.76

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Solution

The fourth proportional to 660.72, 911.46 and 380.76 is: 525.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.72 : 911.46 = 380.76 : x
  2. Step 2: Convert to fraction form
    660.72/911.46 = 380.76/x
  3. Step 3: Cross multiply
    660.72x = 911.46 × 380.76
  4. Step 4: Simplify right side
    660.72x = 347,047.51
  5. Step 5: Solve for x
    x = 347,047.51/660.72
  6. Step 6: Final answer
    x = 525.26

Related Problems

Find fourth proportional to 330.36, 455.73 and 190.38
Half scale
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Double scale
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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.