Statistics and Probability Answers

The mean and standard deviation for the quality grade point averages of a random sample of 28 college seniors are calculated to be 2.6 and 0.3 respectively. Find the 95% confidence interval for the mean of the entire senior class. How large a sample is required if we want to be 95% confident that our estimate of µ is not off by more than 0.05?

Given that event A and B are independent and that P(A)=1/8 and P(A or B)=1/3, find P(B)

Suppose 2 houses in 1000 catches fire in a year & there are 2000 houses in d village. what is d probability of
1 atleast 1 house catches fire?
2 none of the house catch fire?

there are 4 types of toys (a,b,c,d) . There is one toy in each cereal box. A mother buys 6 boxes. Determine the probability that she is able to collect all 4 toys

The following data are the share of foreign shareholding as a percentage of
total market capitalization in Korea for the past 12 years: 5, 10, 10, 12, 13, 14, 18, 21,
30, 37, 37, 40.2 Develop a forecasting model for these data and forecast foreign shareholding
percentage for Korea in the following year.

Over a three year period in Smallsville, Judge Adams saw 37% of the cases, Judge Brown saw 39% of the cases and Judge Carter saw the remainder of the cases. Nine percent of Judge Adams' cases were appealed, 8% of Judge Browns's cases were appealed, and 6% of Judge Carters cases were appealed.

Given a randomly selected case from this three year period was not appealed, what is the probability the judge in the case was not Judge Carter?

What does it mean for two categorical variables to be “independent?” Then, create a contingency table to show us an example of two categorical variables that are not independent and explain why.

The mean math score on the SAT in 2010 was M=516. A student obtains a score of X=483. The college admissions office looks at how you perform relative to the class overall. Would it be better for the student if the standard deviation of the math scores was s=15 or s=75? Explain. (Hint: explain mathematically using z-scores.)

Suppose that a computer is connected to a local network. To send a message the computer is consuming the network for a time frame of a multi seconds exactly. With probability p = 0.8, the transmission is a success but , if the transmission does not work then the computer will make a new attempt to transmit after a random period of time has elapsed, and so on until the transmission has been successfully allocated.
What is the expected total time required to transmit a message if the random delay has a hope than 3 milliseconds?
What is the standard deviation of the total transmission time if the time between transmissions is an integer of milliseconds randomly selected between 1 and 5 inclusive (equal opportunities?)

how to express mean(17) as a percentage of 18 students