Statistics and Probability Answers

A survey of mathematics students at the college revealed that 48% consistently spent at least 1.5 hours on mathematics homework and 52% spent less. Of those who spent at least 1.5 hours on homework, 79% made an A or B in the course. Of those who spent less than 1.5 hours, 26% made an A or B. A student made an A or B in the course. Find the probability that the student spent at least 1.5 hours on homework.

The marketing department of a company has designed three different boxes for its product. It wants to determine which box will produce the largest amount of sales. Each box will be test marketed in five different stores for a period of a month. Information on sales is provided below.

Store 1 Store 2 Store 3 Store 4 Store 5
Box 1 210 230 190 180 190
Box 2 195 170 200 190 193
Box 3 295 275 290 275 265

I know the treatments sum of squares is meant to be 24,467.2, however, whenever I calculate it I always get 25,682.2

The error sum of squares is meant to be 2022.14, but I always get 2733.2.

So can someone give me the specific calculations as to how I'm supposed to get 24,467.2 and 2022.14? Because I can't see anything that I've done incorrectly.

An English professor is attempting to estimate the mean number of novels that the student body reads during their time in college. He is conducting an exit survey with seniors. He hopes to have a margin of error of 3 books with 95% confidence. From reading previous studies, he expects a large standard deviation and is going to assume it is 10. How many students should he survey?

Paul, Joe and Ken are playing soccer. The probability that Paul scores a goal is ¼, that of Joe scoring is 3/5 and that ken scoring a goal is 4/7. Find the probability that in a soccer game:
i. Only two scores a goal
ii. Two of them score a goal
iii. None of them score a goal
iv. At least one of them scores a goal

The masses of a sample of male frogs taken from a pond can be modeled by a normal distribution with a mean mass of 70g and standard deviation 5g. Four male frogs are chosen at random. Find the probability that their mean mass is less than 65g.

The probability that John goes to the show is 1/3. If he goes to the show, the probability that he sees a python is 2/5. If he does not go to the show the probability that he sees a python is 1/8. Find tha probability that;
i. John goes to the show but she doesn’t see a python
ii. John sees a python elsewhere

The probability that a bakery customer will order a birthday cake is .04.
a) What is the expected number of customers until the first birthday cake is ordered?
b) What is the probability the first cake order occurs within the first 20 customers? (Round your answer to 4 decimal places.)

the pew research poll described in exercise 1 found that 49% of a sample of 799 teens admitted to misrepresenting their age online to access websites and online services. ( treat this as a random sample)

a) find the margin of error for this poll if we want 95% confidence in our estimate of the percent of American teens who have misrepresented their age online
b) Explain what that margin of error means
c) if we only need to be 90% confident, will the margin of error be larger or smaller? Explain
d) find that margin or error
e) in general if all other aspects of the situation remain the same would smaller samples produce smaller or larger margin of error?

a 2011 gallup poll found that 76% of Americans believe that high achieving high school students should be recruited to become teachers. this poll was based on a random sample of 1002 Americans

a) find a 90% confidence interval for the proportion of Americans who would agree with this
b)interpret your interval in this context
c)explain what 90% confidence means
d) do these data refute a pundits claim that 2/3 of Americans believe this statement? Explain

A and B play a game in which A's probability of winning is 2/3 in a series of seven games. What is probability that, A will win
(i) 6 or more games
(ii) From 3 to 4 games