Find Probabilities, Mean and Standard Deviation, and Distribution

1. The number of hours needed by students in an economics course to complete a term paper are attached.

A student is selected at random. Find the following probabilities.
a. the student took more than 9 hours
b. the student took less than 6 hours
c. the student took between 7 and 9 hours, inclusive.

2. A box holds 5 blue chips, 14 orange chips, and 6 yellow chips. If a chip is randomly selected, what is the probability that it is yellow?

3. A company makes batteries in batches of 20, with a 3% rate of defects. Find the mean and standard deviation for the random variable x, the number of defects per batch.

4. Find the mean and standard deviation for the random variable x, given the attached distribution

5. The variable x is normally distributed. The mean is 15.2, and the standard deviation is 0.9. if an item is randomly selected, find the probability that it is greater than 16.1.

This solution is provided in an attached .doc file. It goes through each question and briefly calculates and explains how to calculate probability, mean and standard deviation.

... We find the probability of selecting a foreman who ... Finally, we add the two probabilities, so .3413 ... weekly incomes follows the normal probability distribu- tion ...

... C. If only two outcomes are possible for an experiment, then the sum of the probabilities of the outcomes is equal to 1. D ...Find the probability that neither ...

... e. Based on the probability found in the previous part ... females is selected, what is the probability that the ... More than three standard deviations above the mean? ...

...Find the indicated probability. 5) The weekly salaries of teachers in one state are normally distributed with a mean of $490 and a standard deviation...

... 6. The lengths of pregnancies are normally distributed with a mean of 268 days and a standard deviation... Given this information, find the probability of a ...

... 0 + probability of 1 recognize *1+ probability of 2 recognize *2+ probability of 3 recognize *3+ probability of 4 ...Find the indicated probabilities. ...

... of the possible sample sizes find the probability that the ...Find the mean of the variable x 6. A ...mean has approximately normal distribution with mean=1.60 kg ...

... Records from the past several years show the following probabilities of profits (rounded to the nearest $50). ... a) Find the probability that the snowpack is ...