Answer:
The datapoint 9.0 ppm is outlier at the 90% confidence level.
Explanation:
The old data has following values
mean=10.5 mm
standard deviation 0.2 mm
Now the mean of new values is calculated as following

So the value as 9.0 ppm can be considered easily as outlier in this regard.
Answer:
The answer your looking for is option 2 - Inertia
Answer:
Buffers
Explanation:
A buffer solution is a solution containing weak acids and their salts or weak bases and their salts.
A buffer solution is an equilibrium system that resists changes in pH or pOH when a small amount of an acid or base is added hence it is a solution of fairly constant pH value.
The neutral pH is 7. Less than 7 indicates an acid and more than 7 indicates a base (up to 14).
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NaCl - it's a salt (we can't measure the pH)
H2O - it can be an acid but also a base (the pH it is almost neutral,meaning close to 7 )
HF - it is a strong acid
</span><span>
KOH
- it is a strong base (pH=14)
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He needs to use HF (Hydrogen fluoride) to decrease the pH.
The answer is B. the germinal stage