The probability of picking red button is 
<u>Solution:</u>
Given, A jar contains 30 red, 30 blue, and 60 white buttons.
You pick one button at a random choice,
We have to find the probability that it is red button.
Now, total number of buttons = 30 + 30 + 60 = 120 buttons.
Number of favourable cases for red button = 30 red buttons.
The probability of an event is given as:


Thus the probability that it is red is 
Answer:
And rounded up we have that n=656
Step-by-step explanation:
In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 80% of confidence, our significance level would be given by
and
. And the critical value would be given by:
Solution to the problem
The margin of error for the proportion interval is given by this formula:
(a)
Since we don't have prior info for the proportion of interest we can use
as estimator. And on this case we have that
and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
And replacing into equation (b) the values from part a we got:
And rounded up we have that n=656
Answer:

Step-by-step explanation:
We are given a joint probability table.
There are four different graders in a school
1. Grade Ninth
2. Grade Tenth
3. Grade Eleventh
4. Grade Twelfth
Field trip refers to the students who will attending the amusement park field trip.
No field trip refers to the students who will not be attending the amusement park field trip.
We want to find out the probability that the selected student is an eleventh grader given that the student is going on a field trip.

Where P(eleventh and FT) is the probability of students who are in eleventh grade and will be going to field trip

Where P(FT) is the probability of students who will be going to field trip

So the required probability is

The answer would be B. -2 < x < 2 because if you look at the graph, the range would be left and right. So, the farthest to the left would be -2 and the farthest to the right would be 2.
It wouldn't be all real numbers.
<em>Hope this helps! - from peachimin</em>
Answer:
90
Step-by-step explanation:
1125/100=11.25
11.25x8=90