Home / 315.60-472.78-281.20

Finding the Fourth Proportional to 315.60, 472.78 and 281.20

Calculator

Solution

The fourth proportional to 315.60, 472.78 and 281.20 is: 421.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    315.60 : 472.78 = 281.20 : x
  2. Step 2: Convert to fraction form
    315.60/472.78 = 281.20/x
  3. Step 3: Cross multiply
    315.60x = 472.78 × 281.20
  4. Step 4: Simplify right side
    315.60x = 132,945.74
  5. Step 5: Solve for x
    x = 132,945.74/315.60
  6. Step 6: Final answer
    x = 421.25

Related Problems

Find fourth proportional to 157.80, 236.39 and 140.60
Half scale
Find fourth proportional to 631.20, 945.56 and 562.40
Double scale
Find fourth proportional to 316.60, 474.28 and 282.20
Similar ratio
Find fourth proportional to 473.40, 709.17 and 421.80
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.