Answer:
This is an observational study based on a stratified sample.
Step-by-step explanation:
This study aimed to check which clean-up/drying up method after handwashing was more effective; that is, do dryers eliminate more germs than paper towels.
It involved 100 people that took part in the study. The 100 of them contaminated their hands and were instructed to wash their hands with soap and water for 15 seconds before the participants are randomly grouped into two strata; one stratum/group (consisting of 50 participants) that dries their hands with a dryer and another (also consisting of 50 participants) that dry their hands with paper towels.
An observational study is one in which data is collected only by monitoring the events of the study. The conductor of the study in no way tries to intervene or control any of the variables being studied. No control, no tweaking of factors, just observe and record data.
An observational study based on a stratified sample is an observational study that uses the stratified sampling method to carry out its objectives. It randomly puts each of the participants being observed into groups or strata. Each group of randomly assigned participants are then required to run the test for one of the variables being compared.
This is exactly what the study in the question describes. This is why this study is undoubtedly an observational study based on a stratified sample.
Hope this Helps!!!
Answer:
1. What is the period and the amplitude of the sine function representing the position of the band members as they begin to play?
Answer: Amplitude is 80 ft, period is 60 ft.
2. Edna is sitting in the stands and is facing Darla. Edna observes that sine curve begins by increasing at the far left of the field. What is the equation of the sine function representing the position of band members as they begin to play?
Answer: y = 80cos(x*π/30)+80
3. As the band begins to play, band members move away from the edges, and the curve reverses so that the function begins at the far left by decreasing. Darla does not move. The sine curve is now half as tall as it was originally. What is the equation of the sine curve representing the position of the band members after these changes?
Answer: y = 40cos(x*π/30)+80
4. Next, the entire band moves closer to the edge of the football field so that the sine curve is in the lower half of the football field from Edna’s vantage point. What is the equation of the sine curve representing the position of the band members after these changes?
Answer: y = 40cos(x*π/30)+40
Step-by-step explanation:
Answer: $2936.27
Step-by-step explanation:
Present value = $1663
Rate = 5.5%
Time(n) = 19years
Future value= PV(1+r)^n
= 1663(1+5.5%)^19
= 1663(1.055)^19
=1663 × 2.766
=4599.86
Interest = Future value - Present value
= $4599 - $1663
= 2936
2x^3+x^2-15x factored completely would be: <em>x(x+3)(2x-5).</em> Not sure which answer choice but I hope that I was some help.
Answer: 8x+12
Step-by-step explanation:
perimeter equals (x+4) + (3x+2) + (x+4) + (3x+2) = x+4 + 3x+2 + x+4 + 3x+2 = 8x+12
