Home / 430-645-126

Finding the Fourth Proportional to 430, 645 and 126

Calculator

Solution

The fourth proportional to 430, 645 and 126 is: 189

Step by Step Solution

  1. Step 1: Write the proportion equation
    430 : 645 = 126 : x
  2. Step 2: Convert to fraction form
    430/645 = 126/x
  3. Step 3: Cross multiply
    430x = 645 × 126
  4. Step 4: Simplify right side
    430x = 81,270
  5. Step 5: Solve for x
    x = 81,270/430
  6. Step 6: Final answer
    x = 189

Related Problems

Find fourth proportional to 215, 322.50 and 63
Half scale
Find fourth proportional to 860, 1,290 and 252
Double scale
Find fourth proportional to 431, 646.50 and 127
Similar ratio
Find fourth proportional to 645, 967.50 and 189
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.