Answer:
3. Standard deviation is the square root of the variance.
4. Standard deviation is useful because it has the same units as the underlying data.
Step-by-step explanation:
3. In statistics, the dispersion in a given data with respect to its mean distribution can be determined or measured by standard deviation and variance. The standard deviation of a distribution can also be determined as the square root of variance.
4. Standard deviation is measured in the same units as that of the original data. Thus it has the same units as the underlying data.
At sea level atmospheric pressure is 1 bar absolute (1 standard atmosphere =101 kPa=1.013 bars). The weight of the atmosphere exerts a pressure which will support a column of water 10 m high; 10 m under water the pressure on a diver is 200 kPa. The volume of gas in an early diving bell full of air at sea level is halved at 10 m according to Boyle’s law; at 20 m pressure is 300 kPa absolute and the gas is compressed into one third the volume.
Dry air is composed of roughly 21% oxygen, 78% nitrogen, and 1% other gases. According to Dalton’s law the partial pressure of oxygen at any depth will be 21% of the total pressure exerted by the air and the partial pressure of nitrogen will be 78% of total pressure.
Gases dissolve in the liquid with which they are in contact. Nitrogen is fat soluble and at sea level we have several litres dissolved in our bodies. If the partial pressure of nitrogen is doubled (by breathing air at 10 m depth) for long enough for equilibration to take place we will contain twice as many dissolved nitrogen molecules as at sea level.
Answer:
Empirical formula= COOH
Step-by-step explanation:
Molecular mass of the elements
Carbon= 12
Oxygen= 16
Hydrogen= 1
We divide the elements each with their molecular formula
Carbon= 2.4/12
Carbon= 0.2
Oxygen= 6.4/16
Oxygen= 0.4
Hydrogen= 0.2/1
Hydrogen= 0.2
Now we divide with the smallest result which is 0.2
Carbon= 0.2/0.2
Carbon = 1
Oxygen= 0.4/0.2
Oxygen= 2
Hydrogen= 0.2/0.2
Hydrogen= 1
So we have
Carbon 1, oxygen 2, hydrogen 1
Empirical formula= COOH
Type of lines ? Not the best question.
Answer: Perpendicular, first choice
The little 90 degree angle indicator at the intersection marks these lines as meeting at a right angle, which is called perpendicular.
Answer:
-4
Step-by-step explanation:
-10 - (-6)
Remove the brackets:
-10 - - 6
Remember that all negative and negative values are always positive because they are the same; if they are different, for instance, a positive value and a negative value, then that value will be a negative value.
Continue solving:
-10 - - 6
- and - are positive values
- 10 + 6
= - 4
Therefore the answer is 4
