A scientist who studies sleep has developed a new technique to help people sleep each night. He is conducting a study of 100 people and wants to determine if there is significant difference in people's amount of sleep before using the technique compared to after using the technique. Which of the following describes the scientist's null and alternative hypotheses?
1. null hypothesis: Up = 0; alternative hypothesis: 4p 70
2. null hypothesis: Lo + 0; alternative hypothesis: 4p = 0
3. null hypothesis: 4 - 4y = 0; alternative hypothesis: 44-470
4. null hypothesis: 44-42 +0; alternative hypothesis: 44-42 = 0

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.

d

step-by-step explanation:

yes, whats the problem?

the answer is c.

perimeters = 3√10/5

areas = 90/25

i got it down chief.