In: Statistics and Probability
A particular lake is known to be one of the best places to catch a certain type of fish. In this table, x = number of fish caught in a 6-hour period. The percentage data are the percentages of fishermen who caught x fish in a 6-hour period while fishing from shore.
x | 0 | 1 | 2 | 3 | 4 or more |
---|---|---|---|---|---|
% | 43% | 35% | 15% | 6% | 1% |
(b) Find the probability that a fisherman selected at random
fishing from shore catches one or more fish in a 6-hour period.
(Enter a number. Round your answer to two decimal places.)
(c)Find the probability that a fisherman selected at random
fishing from shore catches two or more fish in a 6-hour period.
(Enter a number. Round your answer to two decimal places.)
(d) Compute μ, the expected value of the number of fish caught
per fisherman in a 6-hour period (round 4 or more to 4). (Enter a
number. Round your answer to two decimal places.)
μ = fish
(e) Compute σ, the standard deviation of the number of fish
caught per fisherman in a 6-hour period (round 4 or more to 4).
(Enter a number. Round your answer to three decimal places.)
σ = fish
SOLUTION:
From given data,
(a) Convert the percentages to probabilities and make a histogram of the probability distribution.
(b) Find the probability that a fisherman selected at random fishing from shore catches one or more fish in a 6-hour period.
the probability that a fisherman selected at random fishing from shore catches one or more fish in a 6-hour period.
= 0.35+0.15+0.06+0.01 =0.57
(c) Find the probability that a fisherman selected at random fishing from shore catches two or more fish in a 6-hour period.
the probability that a fisherman selected at random fishing from shore catches two or more fish in a 6-hour period.
= 0.15+0.06+0.01 =0.22
(d) Compute μ, the expected value of the number of fish caught per fisherman in a 6-hour period (round 4 or more to 4). (Enter a number. Round your answer to two decimal places.) μ = fish
We simplify the value of
x=4 or more as x=4
Hence,
X | Probability (p) | P*X | X2 | P*X2 |
0 | 0.43 | 0 | 0 | 0 |
1 | 0.35 | 0.35 | 1 | 0.35 |
2 | 0.15 | 0.3 | 4 | 0.6 |
3 | 0.06 | 0.18 | 9 | 0.54 |
4 | 0.01 | 0.04 | 16 | 0.16 |
Total | 1 | 0.87 | 1.65 |
Expected value =
(e) Compute σ, the standard deviation of the number of fish caught per fisherman in a 6-hour period (round 4 or more to 4). (Enter a number. Round your answer to three decimal places.) σ = fish
Standard deviation =
=