When investigating a sample of 556 men working in a cadmium pigment plant, it was found that the cadmium in a man's urine was linearly related to the number of years worked in the plant. The estimated slope of the line obtained by regressing the amount of cadmium against years worked was 0.9 μg/l per year, with 95% confidence interval extending from 0.6 μg/l to 1.2 μg/l. The intercept was not significantly different from zero. Select all of the following statements which you believe to be true.
Note: There is only one correct answer below. Units of measurement of cadmium concentration in urine are microgram per liter, denoted by μg/l.
