Adding chalk to water, white chalk specks formed from this an example of what ?

The yearly amounts of carbon emissions from cars in belgium are normally distributed with a mean of 13.9 gigagrams per year and a standard deviation of 5.8 gigagrams per year. find the probability that the amount of carbon emissions from cars in belgium for a randomly selected year are between 11.5 gigagrams and 14.0 gigagrams per year. a. 0.340 b. 0.660 c. 0.167 d. 0.397

Avariable that is not being directly tested during an experiment should be

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?