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
Answer:
20 in³
Step-by-step explanation:
Area of a triangle is half the base times the perpendicular height:
A=0.5bh
=0.5*10*4
=20
Answer:
1st, 3rd, and 6th
Step-by-step explanation:
Let's look at each statment...
1.) Correct
Explanation: 10 percent of the students at the school participate in soccer. If 140 is 10% of the number of students at the school, there is more than 140 students at this school.
2.) Incorrect
Explanation: We've already established that the # of students at the school is <u>more</u> than 140.
3.) Correct
Explanation: 10% as a decimal is 0.1 Divide 140 by 0.1 and you get 1,400. So, the total number of students is 1,400.
4.) Incorrect
Explanation: We've already established that the number of students is 1,400, not 290.
5.) Incorrect
Explanation: We've already established that the number of students is 1,400, not 150.
6.) Incorrect
Explanation: If the percent was a ratio, it would be 10:100 or 10/100. This is because a whole percent is 100% and the percent of students who play soccer is 10%.
7.) Correct
Explanation: We've already established that the ratio would be 10:100 or 10/100. Thus, this is correct.
I hope this helps! :)
Because the angles are supplementary, they add to 180 degrees.
I solved this by dividing
which gives me 30 degrees.
multiply 30 by 5 gives you 150.
and 30 + 150 = 180
