Answer: 1/4 round.
Step-by-step explanation:
Grace has 3 wheels of cheese and she wants to eat an equal amount each day for 12 days. So each wheel needs to last 12/3 = 4 days. So then she can eat 1 wheel/4 days = 1/4 wheel per day.
<u>First problem :</u>
probability to draw a red paper : 42/(42+18)=7/10
In 110 tries one can thus expect to draw 7/10*110=77 red papers
<u>Second problem :</u>
Since for 150 trials (which will give the least error) we have got 135 yellow balls, we can expect twice as much in 300=150*2 trials, which makes 270 yellow balls.
First, we are going to find the common ratio of our geometric sequence using the formula:

. For our sequence, we can infer that

and

. So lets replace those values in our formula:


Now that we have the common ratio, lets find the explicit formula of our sequence. To do that we are going to use the formula:

. We know that

; we also know for our previous calculation that

. So lets replace those values in our formula:

Finally, to find the 9th therm in our sequence, we just need to replace

with 9 in our explicit formula:



We can conclude that the 9th term in our geometric sequence is <span>
1,562,500</span>
Answer:

And using the cumulative distribution function we got:

The probability that preparation is within 2 minutes of the mean time is 0.134
Step-by-step explanation:
For this case we define the following random variable X= (minutes) for a lab assistant to prepare the equipment for a certain experiment , and the distribution for X is given by:

The cumulative distribution function is given by:

The expected value is given by:

And we want to find the following probability:

And we can find this probability on this way:

And using the cumulative distribution function we got:

The probability that preparation is within 2 minutes of the mean time is 0.134