Home / 310.50-428.24-217.20

Finding the Fourth Proportional to 310.50, 428.24 and 217.20

Calculator

Solution

The fourth proportional to 310.50, 428.24 and 217.20 is: 299.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.50 : 428.24 = 217.20 : x
  2. Step 2: Convert to fraction form
    310.50/428.24 = 217.20/x
  3. Step 3: Cross multiply
    310.50x = 428.24 × 217.20
  4. Step 4: Simplify right side
    310.50x = 93,012.64
  5. Step 5: Solve for x
    x = 93,012.64/310.50
  6. Step 6: Final answer
    x = 299.56

Related Problems

Find fourth proportional to 155.25, 214.12 and 108.60
Half scale
Find fourth proportional to 621, 856.47 and 434.40
Double scale
Find fourth proportional to 311.50, 429.61 and 218.20
Similar ratio
Find fourth proportional to 465.75, 642.35 and 325.80
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.