Answer:
Is an experimental study
Step-by-step explanation:
In an observational study you don't control any aspect of the investigation you just observe the variables that you determined since the beginning without any intervention.
In this case you are controlling who sees one or the other video, then you are controlling one of the variables that is the type of video each group sees and because of this it is an experimental study. Researchers designed an experiment to prove the null hypothesis they had.
Answer:
The answer is 60.11
Step-by-step explanation:
An adult person receives 425 pieces of mail each year with a standard deviation of 50.
Now, we have the following details :
Mean of sample = 425
sigma = 50
Standard error = 
= 
= 60.11
Answer:
Expected time is 15 hours for him to get to safety.
Step-by-step explanation:
We define X as the time that this miner would get to safety.
We define Y as the door he chooses initially.
P(Y= 1) = P(Y=2)=P(Y=3) = 1/3
We have E[X|Y=1] = 3
E[X|Y] = 5 hours + E[X}
E[X|Y] = 7 hours + E[X]
Then we have
E[X] = 1/3(3 + 5 + E[X] + 7 + E[X])
We cross multiply
3*E[X] = (15 + 2E[x])
3E[X] - 2E[X] = 15
E[X] = 15
So the time it would take to get him to safety is 15 hours
The false statement is (c) the probability of selecting a blue or yellow marble is less than the probability of selecting a red or green marble.
<h3>What are probabilities?</h3>
Probabilities are used to determine the chances of events
The table entry is given as:
- Red - 2
- Blue - 3
- Yellow - 4
- Green - 3
From the list of options, the false statement is
(c) the probability of selecting a blue or yellow marble is less than the probability of selecting a red or green marble.
This is so because:
- Blue or Yellow = 3 + 4 = 7
- Red or Green = 2 + 3 = 5
Notice the count of blue or yellow marbles (7) is greater than the number of red or green marbles (5)
This means that, the probability of selecting a blue or yellow marble is greater than the probability of selecting a red or green marble.
Read more about probabilities at:
brainly.com/question/251701
Answer:
Step-by-step explanation:
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Given:
---------->>>>
Collect like terms.
---------->>>>
Simplify
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Hope this is helpful.
