Thus, a genotype's frequency will decline or increase depending on whether its fitness is lower or greater than the mean fitness, respectively. In the particular case that there are only two genotypes of interest (e.g. representing the invasion of a new mutant allele), the change in genotype frequencies is often written in a different form.
1 Places such as Lowes and Home Depot will charge around $60 per day. 2  According to DoItYourself.com, they claim that average daily rental is going to be around $60 per day. 3  They also note that a good pressure washer should cost you around $350. 4  SunbeltRentals.com offers a variety of pressure washers.
Re: Pressure washer Pump Saver. I buy the aerosol type pump conditioner from Sears, or from Lowe's in a pinch (the cans are smaller from Lowe's). I only use it every five or so uses, or when the PW will be stored for some time or if a freeze is expected. Not much freezing in my area, but our water is as hard as rock.