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Finding the Fourth Proportional to 565.71, 780.72 and 390.75

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Solution

The fourth proportional to 565.71, 780.72 and 390.75 is: 539.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    565.71 : 780.72 = 390.75 : x
  2. Step 2: Convert to fraction form
    565.71/780.72 = 390.75/x
  3. Step 3: Cross multiply
    565.71x = 780.72 × 390.75
  4. Step 4: Simplify right side
    565.71x = 305,066.34
  5. Step 5: Solve for x
    x = 305,066.34/565.71
  6. Step 6: Final answer
    x = 539.26

Related Problems

Find fourth proportional to 282.86, 390.36 and 195.38
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.