1. ## Relative Frequency

Farmer Jones has planted a wheat crop. For the wheat crop to be successful, farmer Jones needs 500 mm of rain to fall over the spring months. Past weather records show that this has occurred 27 of the past 60 years. Find the relative frequency of:

(i) sufficient rainfall

(ii) insufficient rainfall

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My attempt: each year has three months of spring, means there are 180 months of springs in 60 years.

(i) 27/180 = 3/20

(ii) 153/180 = 17/20

2. ## Re: Relative Frequency

Originally Posted by joshuaa
Farmer Jones has planted a wheat crop. For the wheat crop to be successful, farmer Jones needs 500 mm of rain to fall over the spring months. Past weather records show that this has occurred 27 of the past 60 years. Find the relative frequency of:

(i) sufficient rainfall

(ii) insufficient rainfall

----------------------------------

My attempt: each year has three months of spring, means there are 180 months of springs in 60 years.

(i) 27/180 = 3/20

(ii) 153/180 = 17/20
During the 27 years that it occurred, you are suggesting it only occurred in one month during the spring. There are three months of spring in which there was sufficient rainfall.

3. ## Re: Relative Frequency

"Compare" years with years or months with months. A fraction with "years" in the numerator and "months" in the denominator makes no sense. There was sufficient rainfall in 27 of the past 60 years so the relative frequency was $\frac{27}{60}= \frac{9}{20}$. If you want to argue that 60 years is 180 "months of spring" then you should also say the 27 years when there was sufficient rainfall was 81 months of spring: $\frac{81}{180}= \frac{9}{20}$ again.

4. ## Re: Relative Frequency

thanks a Lot. I got my mistake.