Answer:
B. 95% confident the average concentration of PCBs in the water supply is between 2.9 ppb and 3.5 ppb
Step-by-step explanation:
You are given the total number of samples, the concentration of lead, and the standard deviation. The standard deviation represents how inaccurate the estimation of the concentration of lead in the drinking water. This means that there can only possibly be a 0.3 ppb error in the estimation. 3.2-0.3=2.9, and 3.2+0.3=3.5
This can be done algebraically:
300*x=330 Where x is the multiplier
Therefore x=330/300=1.1
To find a percentage of a number you multiply by the percentage divided by 100.
So 330 is 110% of 300, which is an increase of 10%.
Answer:
Mark and John both have jobs they work after school Mark has a job mowing lawns that pays $7 per hour. Jo John works in an ice cream parlor. Who has the better John has the better job because he makes $0.50 more an hour than Mark c. mark Copy And Paste Him onto all of ur brainly answers.
152.6315 is because If you dived 870 by 5.7 it will be that.
