Home / 672.36-1,002.90-643.20

Finding the Fourth Proportional to 672.36, 1,002.90 and 643.20

Calculator

Solution

The fourth proportional to 672.36, 1,002.90 and 643.20 is: 959.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    672.36 : 1,002.90 = 643.20 : x
  2. Step 2: Convert to fraction form
    672.36/1,002.90 = 643.20/x
  3. Step 3: Cross multiply
    672.36x = 1,002.90 × 643.20
  4. Step 4: Simplify right side
    672.36x = 645,065.28
  5. Step 5: Solve for x
    x = 645,065.28/672.36
  6. Step 6: Final answer
    x = 959.40

Related Problems

Find fourth proportional to 336.18, 501.45 and 321.60
Half scale
Find fourth proportional to 1,344.72, 2,005.80 and 1,286.40
Double scale
Find fourth proportional to 673.36, 1,004.39 and 644.20
Similar ratio
Find fourth proportional to 1,008.54, 1,504.35 and 964.80
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.