Answer:
0.923
Step-by-step explanation:
There are 13 total marbles. (12 Purple Marbles + One Blue Marble)
The total events are 13 and the number of preferred events is 12.
≈ 0.923
So there should be a 0.923 chance that a purple marble is picked.
Answer: a) 15, b) 1.
Step-by-step explanation:
A researcher studying public opinion of proposed social security changes obtains a simple random sample of 35 adult Americans and asks them whether or not they support the proposed changes. To say that the distribution of the sample proportion of adults who respond yes, is approximately normal, how many more Americans does the researcher need to sample in the following cases?
(a) 10% of all adult Americans support the changes
Here, 
And , 
So, consider the equality, to find the value of 'n'.

So, there are
more adult Americans needed.
(b) 15% of all adult Americans supports the changes
Here, 
So, again we get that

So, there are
more adult Americans needed.
Hence, a) 15, b) 1.
Answer: 14 a hour
Step-by-step explanation: