Answer:
a) 1.8 × 10^-12 cm³ or 1.8 × 10^-12 cubic meters
b) 7.1 × 10^-6 mm² or 7.1 × 10^-6 square millimeters
Step-by-step explanation:
a) We are assuming that the shape of the bacteria is a sphere.
Hence, Volume of the Sphere(Bacteria) = 4/3 × π × r³
Diameter = 1.5 μm
Radius = Diameter/2 = 1.5μm/2
= 0.75μm
We are told that the volume should be in cubic centimeters
Converting 0.75μm to centimeters
1 μm = 1 × 10^-4 cm
0.75 μm =
Cross Multiply
= 0.75 μm × 1 × 10^-4 cm/ 1 μm
= 0.000075cm
Volume of the Sphere(Bacteria) = 4/3 × π × r³
= 4/3 × π × (0.000075)³
= 1.767145867 × 10^-12 cm³
Approximately as 2 significant figures = 1.8 × 10^-12 cm³
b) The formula for the Surface area of a Sphere = 4πr²
Diameter = 1.5 μm
Radius = Diameter/2 = 1.5μm/2
= 0.75μm
We are told that the surface area should be in square millimeters
Converting 0.75μm to millimeters
1 μm = 0.001 mm
0.75 μm =
Cross Multiply
= 0.75 μm ×0.001mm/ 1 μm
= 0.00075mm
Surface Area of a Sphere
= 4 × π × r²
= 4 × π × 0.00075²
= 7.06858 ×10^-6 mm²
Approximately to 2 significant figures
= 7.1 × 10^-6 mm²
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:
yes
Step-by-step explanation:
The graph is of a function (one output for every input) that also passes the horizontal line test (one input for every output). Hence it is one-to-one.
For a <em>function</em>, the key for it being one-to-one is that it pass the horizontal line test.
