Exercise · ZW-UNIFORM-DISTRIBUTION-007 · ★★☆ Intermediate
A uniform variable on \([a,b]\) has mean 5 and variance 3. What is the interval?
Choose one option.
Show answer
- D. \([2,8]\)
Explanation
From \((b-a)^2/12=3\) we get \(b-a=6\); with \((a+b)/2=5\) this gives \(a=2\), \(b=8\).
Review the concept: Uniform distribution
A continuous uniform variable takes values in an interval with the same density at every point, so intervals of equal length have equal probability.
\[f(x)=\frac{1}{b-a},\quad a\le x\le b\]
More practice problems: uniform distribution
- ZW-UNIFORM-DISTRIBUTION-001 If X is uniform on [0,4], find P(X<1).
- ZW-UNIFORM-DISTRIBUTION-002 If X is uniform on [2,6], find E[X].
- ZW-UNIFORM-DISTRIBUTION-003 If X is uniform on [1,5], what is its density at x=3?
- ZW-UNIFORM-DISTRIBUTION-004 If X is uniform on [0,10], find P(3<X<7).
- ZW-UNIFORM-DISTRIBUTION-005 If X is uniform on [-1,3], find P(X>0).
- ZW-UNIFORM-DISTRIBUTION-006 If X is uniform on [0,6], find Var(X).
- ZW-UNIFORM-DISTRIBUTION-008 If X is uniform on [2,8], find F(5)=P(X≤ 5).
- ZW-UNIFORM-DISTRIBUTION-009 If X is uniform on [0,1], find P(X<0.3| X<0.6).