Home / 419.09-628.58-213.81

Finding the Fourth Proportional to 419.09, 628.58 and 213.81

Calculator

Solution

The fourth proportional to 419.09, 628.58 and 213.81 is: 320.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.09 : 628.58 = 213.81 : x
  2. Step 2: Convert to fraction form
    419.09/628.58 = 213.81/x
  3. Step 3: Cross multiply
    419.09x = 628.58 × 213.81
  4. Step 4: Simplify right side
    419.09x = 134,396.69
  5. Step 5: Solve for x
    x = 134,396.69/419.09
  6. Step 6: Final answer
    x = 320.69

Related Problems

Find fourth proportional to 209.55, 314.29 and 106.91
Half scale
Find fourth proportional to 838.18, 1,257.16 and 427.62
Double scale
Find fourth proportional to 420.09, 630.08 and 214.81
Similar ratio
Find fourth proportional to 628.64, 942.87 and 320.72
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.