Answer: 
Explanation:
Given : Sample size : n= 30 , it means it is a large sample (n≥ 30), so we use z-test .
Significance level : 
Critical value: 
Sample mean : 
Standard deviation : 
The formula to find the confidence interval is given by :-
i.e. 
i.e. 
Hence, the 95% confidence interval for the mean mpg in the entire population of that car model =
Answer:
density=1.43 g/L
Explanation:
Since the density formula is density = mass / volume, we need to find out the mass of the gas and the volume is that of the container.
The mass of the gas is 130.0318 g-129.6375 g=0.3943 g
The gas volume is 276mL*(1L/1000mL) 0.276 L
density = mass / volume=0.3943g/0.276L
density =1.43g/L
A. True
They are formed behind an obstacle when the wind blows the sand up to it.
The correct answer is (a) wave the fumes toward your nose with your hand. If you smell the chemicals directly, it could be harmful too your health, especially if they are strong. Also remember to <em>never </em>smell chemicals unless you are being told to do so.
Explanation:
Steps followed to practice laboratory safety during the experiment are as follows.
- Used tongs or a test tube holder to hold materials over the Bunsen burner flame.
- Wore gloves and goggles.
- Made careful observations of the products and reactants.
- Did not smell the gases produced.
When we heat a test tube over bunsen flame then the tube gets hot and when we hold it with bare hands then out hands will burn. Therefore, it is advised to hold test tube with the help of tongs or a holder so that our hands did not burn.
We should also wear gloves and goggles so that any acid would not spill directly on our hands, skin and eyes as it can affect or damage the skin severely.
Careful observations were made so that correct calculations about the experiment can be carried out.
It is also advised that we should not smell the gases produced but gases move freely from one place to another in a laboratory or any where else.
So, we can try to avoid it by covering our mouth with a cloth but we cannot stop it. If we keep on inhaling the gases produced in a laboratory then it can also lead to severe disease or defect in the human body.
