Home / 453.40-679.98-128.79

Finding the Fourth Proportional to 453.40, 679.98 and 128.79

Calculator

Solution

The fourth proportional to 453.40, 679.98 and 128.79 is: 193.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    453.40 : 679.98 = 128.79 : x
  2. Step 2: Convert to fraction form
    453.40/679.98 = 128.79/x
  3. Step 3: Cross multiply
    453.40x = 679.98 × 128.79
  4. Step 4: Simplify right side
    453.40x = 87,574.62
  5. Step 5: Solve for x
    x = 87,574.62/453.40
  6. Step 6: Final answer
    x = 193.15

Related Problems

Find fourth proportional to 226.70, 339.99 and 64.40
Half scale
Find fourth proportional to 906.80, 1,359.96 and 257.58
Double scale
Find fourth proportional to 454.40, 681.48 and 129.79
Similar ratio
Find fourth proportional to 680.10, 1,019.97 and 193.19
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.