Home / 646.08-897.80-639.40

Finding the Fourth Proportional to 646.08, 897.80 and 639.40

Calculator

Solution

The fourth proportional to 646.08, 897.80 and 639.40 is: 888.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.08 : 897.80 = 639.40 : x
  2. Step 2: Convert to fraction form
    646.08/897.80 = 639.40/x
  3. Step 3: Cross multiply
    646.08x = 897.80 × 639.40
  4. Step 4: Simplify right side
    646.08x = 574,053.32
  5. Step 5: Solve for x
    x = 574,053.32/646.08
  6. Step 6: Final answer
    x = 888.52

Related Problems

Find fourth proportional to 323.04, 448.90 and 319.70
Half scale
Find fourth proportional to 1,292.16, 1,795.60 and 1,278.80
Double scale
Find fourth proportional to 647.08, 899.19 and 640.40
Similar ratio
Find fourth proportional to 969.12, 1,346.70 and 959.10
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.