In: Statistics and Probability
The frequency distribution shown in the following table lists the number of hours per day a randomly selected sample of teenagers spent watching television. Where possible, determine what percent of the teenagers spent the following number of hours watching television. (Round your answers to one decimal place. If not possible, enter IMPOSSIBLE.)
Hours per day | Number
of Teenagers |
---|---|
0 ≤ x < 1 | 17 |
1 ≤ x < 2 | 31 |
2 ≤ x < 3 | 24 |
3 ≤ x < 4 | 37 |
4 ≤ x < 5 | 27 |
5 ≤ x < 6 | 11 |
6 ≤ x < 7 | 15 |
(a) less than 4 hours
%
(b) at least 5 hours
%
(c) at least 1 hour
%
(d) less than 2 hours
%
(e) at least 2 hours but less than 4 hours
%
(f) more than 3.5 hours
%
The table for probability distribution is ,
Hours per day | Number of Teenagers | Probability |
0x<1 | 17 | 17/162=0.1049 |
1x<2 | 31 | 31/162=0.1914 |
2x<3 | 24 | 24/162=0.1481 |
3x<4 | 37 | 37/162=0.2284 |
4x<5 | 27 | 27/162=0.1667 |
5x<6 | 11 | 11/162=0.0679 |
6x<7 | 15 | 15/162=0.0926 |
Sum | 162 | 1 |
(a) P(less than 4 hours)=P(X=3)+P(X=2)+P(X=1)+P(X=0)= 0.2284+0.1481+0.1914+0.1049=0.673=67.3%
(b) P(at least 5 hours)=P(X=5)+P(X=6)=0.0679+0.0926=0.161=16.1%
(c) P(at least 1 hour)=1-P(\ess than 1 hour)=1-P(X=0)=1-0.1049=0.895=89.5%
(d) P(less than 2 hours)=P(X=1)+P(X=0)=0.1914+0.1049=0.296=29.6%
(e) P(at least 2 hours but less than 4 hours)=P(2X<4)=0.1481+0.2284=0.377=37.7%
(f) P(more than 3.5 hours)=P(X=4)+P(X=5)+P(X=6)=0.1667+0.0679+0.0926=0.327=32.7%