Researchers collected data to examine the relationship between pollutants and pre-term births in Southern California. During the study air pollution levels were measured by air quality monitoring stations. Specifically, levels of carbon monoxide were recorded in parts per million, nitrogen dioxide and ozone in parts per hundred million, and course particulate matter (PM_10) in µg/m3. Length of gestation data were collected on 143,196 births between the years 1989 and 1993, and air pollution exposure during gestation was calculated for each birth. The analysis suggested that increased ambient PM_10 and to a lesser degree, CO concentrations may be associated with the occurrence of preterm births. a. The paragraph above describes an
A. Observational Study
B. Experiment
b. The cases in this research are
A. Each birth between 1989 and 1993
B. Each type of pollution measured by air quality monitoring stations
C. Each year between 1989 and 1993
D. Air pollution exposure during gestation
c. What is the research question?
A. How much air pollution is there in Southern California?
B. How prevalent was preterm birth during the years 1989 to 1993?
C. Are preterm births associated with air pollution levels?
D. How can expectant mothers avoid air pollution?
d. What is the population of interest?
A. All human babies
B. All years for which air quality has been measured
C. All environmental pollutants
D. All air quality monitoring stations
e. What is the sample?
A. The pollution measurements for the 4 pollutants
B. Al air quality monitoring stations
C. The 143,196 births
D. The years between 1989 and 1993

step-by-step explanation:

12: 00 p.m. to 7: 00 p.m. is a total of 7 hours.

4: 00 p.m. to 7: 00 p.m. is a total of 3 hours.

this means that from 4: 00 p.m to 7: 00 p.m. this represents 3/7 of what was lost from 12: 00 p.m. to 7: 00 p.m.

after knowing this, after doing 11,600 - 6,800 = 4,800

4,800 represents 3/7 of what was lost for 7 hours.

we then divide 4,800 by 3 which gets 1,600.

because we know that 1,600 represents 1/7 of how much water was lost, we just have to multiply by 7, which gets 11,200.   after adding 11,200 to how much water was left at 7: 00 p.m. which was 6,800. 11,200 + 6,800 = 18,000

this means that the pool originally had 18,000 gallons in the pool.

you can also check your work by doing 18,000 - 4(1600), which becomes           1800 - 6400 which gets you 11,600.

for the friend request.

when a figure, such as triangle (xyz) is reflected over the line y = x to create x'y'z' the x-coordinates and y-coordinates of the original image (pre-image) will be reversed for the image. (e.g., (x, y) > (y, x)) this means that the pre-image position of the x- and y-coordinates switch places which in turn provides a mirror like image of the original xyz.  

i notice that when i draw a line segment from x to x', that the points are parallel from each other -- they are exactly across from each other and do not intersect with any other points.  

yes, think i would see the same characteristic if you drew the line segment connecting y with the reflecting line and then y' with the reflecting line because of the essence of reflections. because it is a mirror image, each point was effected the same way which leads me to conclude that they same would apply to y and y'.

[2, 2.5)

(2.5, 3]

step-by-step explanation:

i think its these two not sure [2, 2.5)

(2.5, 3]