# relative frequency & probability

• Jan 13th 2009, 01:33 PM
nikk
relative frequency & probability
Weather records for WA include information about rainfall in Bunbury and Geraldton.

For Bunbury, the average number of wet days each month is:

J F M A M J J A S O N D
2 2 4 7 14 18 20 17 14 11 6 4

For Geraldton, the average number of wet days each month is:

J F M A M J J A S O N D
2 2 3 6 10 14 15 13 9 7 4 2

use relative frequency to estimate
a) the probability that is rains in Bunbury on June 15 next year.
b) the probability that is rains in Geraldton on June 15 next year.
c) the probability that is does not rain in Bunbury next Christmas day.

ans:
a) 0.6
b) 0.047
c) 0.87

• Jan 13th 2009, 02:05 PM
nvv
Hi, nikk

a) The average number of wet days in June for Bunbury is 18 and number of in June is 30 so probability that is rains in Bunbury on June 15 next year is 18 / 30 = 0.6

b) The average number of wet days in June for Geraldton is 14 and number of in June is 30 so probability that is rains in Bunbury on June 15 next year is 14 / 30 = 0.4666 (I think You have a mistake in your answer)

c) The average number of wet days in December for Geraldton is 4(so there are 27 'dry' days) and number of days is 31 so prob. is 27 / 31 = 0.87
• Jan 13th 2009, 04:34 PM
nikk
Quote:

Originally Posted by nvv
Hi, nikk

a) The average number of wet days in June for Bunbury is 18 and number of in June is 30 so probability that is rains in Bunbury on June 15 next year is 18 / 30 = 0.6

b) The average number of wet days in June for Geraldton is 14 and number of in June is 30 so probability that is rains in Bunbury on June 15 next year is 14 / 30 = 0.4666 (I think You have a mistake in your answer)

c) The average number of wet days in December for Geraldton is 4(so there are 27 'dry' days) and number of days is 31 so prob. is 27 / 31 = 0.87

i will check my ans