Please think of an example of a value that you have seen or heard recently, and then tell us if this is qualitative or quantitative, is it discrete or continuous, and is it nominal, ordinal, interval, or ratio level of measurement. Classmates, do you agree with this categorization? Why or why not? These can be tricky to sort out, so we may have some back-and-forth discussion on these.

An air conditioning company servicing a certain machine room guarantees that the temperature in the room stays below 20o C. Due to malfunctioning of the equipment operating in the machine room, it is suspected that the average temperature actually exceeds 20o for more or less extended periods of time. Seven temperature measurements are collected throughout the day and the following temperatures are observed, 20.8, 20.2, 20.9, 21.5, 22.2, 21.2, 19.8. Assuming that the temperature is at least approximately normally distributed,

a) can you say at a 5% significance level that the room temperature is actually above 20o C?

b) what is the (approximate) p-value for this test? What does it tell you about the conclusion you have just made regarding the room temperature?

c) What is the probability that this test fails to reject Ho even though the true mean temperature is 21o C?

Analysis Paper on : The impact of family structure on the health of children: Effects of divorce.

A sample of final exam scores is normally distributed with a mean equal to 23 and a variance equal to 16.

Part (a)

What percentage of scores are between 19 and 27? (Round your answer to two decimal places.)

Part (b)

What raw score is the cutoff for the top 10% of scores? (Round your answer to one decimal place.)

Part (c)

What is the proportion below 17? (Round your answer to four decimal places.)

Part (d)

What is the probability of a score less than 29? (Round your answer to four decimal places.)

The strategy of the courtroom is a subtle thing. Common sense would say that a criminal who admits guilt is treated more leniently while a defiant criminal gets a harsher sentence. To see if this is actually true, data was gathered from criminal courts to determine if criminals who plead guilty receive lighter sentences than those who plead guilty.

Variables:

a) sentence: Sentence Length (in months).
b) served: Actual sentence served (in months).
c) plea: either a not guilty plea or a guilty plea.

Sentence Served Plea
24 8.75 Not Guilty
33.5 6.5 Not Guilty
25.5 6.5 Gulity
18 12.5 Not Guilty
18.5 11 Gulity
44.5 14.5 Not Guilty
38.5 20 Not Guilty
50.5 22 Not Guilty
12.5 1 Gulity
102 10.75 Gulity
30 1.5 Gulity


Perform a two sample t-test to compare the sentences served by those who plead guilty and those who do not.

State and address all of the assumptions required for the t-test.

Use boxplots to illustrate your data, and describe how they relate to your results.

Do criminals who plead guilty get more lenient treatment than those that plead not guilty? As much as possible, relate your comments to specific results.

The Federal Drug Administration wishes to determine whether the claims that Vitamin C prevents colds has any truth. In a clinical drug trial, 30 subjects were randomly assigned to either the Vitamin C group (receiving a daily supplement of the minimum daily requirement) or the placebo group (who received no supplement but did get a placebo pill). The number of self- reported colds is recorded after three years. Number of colds in 3 years: Vitamin C group: 3, 8, 6, 7, 4, 9, 2, 5, 7, 11, 10, 8, 7, 6, 7 Placebo group: 8, 8, 7, 10, 11, 4, 3, 7, 6, 8, 4, 10, 6, 8,5 The value of the numerator (either + or -) in the t test formula for Problem 3 is _____. Then what is the degrees of freedom and what is the derived t value ? Also, what can be concluded from the statistical analysis and what significance level should be reported?

(I want to compare my answers to yours, because I have different answers than what was given to me earlier on this site, and I don;t understand why...thank you.)

In a town, 36% of the citizens contributed to the Republicans, 46% contributed to the Democrats, and 12% contributed to both. What percentage contributed to neither party?

A box contains 4 white, 3 red, and 3 black marbles. One marble is chosen at random, and it is not black. Find the probability that it is white. (Enter your answer as a fraction.)

Suppose that 90% of drivers are "careful" and 10% are "reckless." Suppose further that a careful driver has a 0.2 probability of being in an accident in a given year, while for a reckless driver the probability is 0.3. What is the probability that a randomly selected driver will have an accident within a year? (Enter your answer to two decimal places.)

Companies X, Y and Z all manufacture a specific component required to make a touch screen tablet. Of these three companies, X shipped 1024 components, Y shipped 512 and Z shipped 256. The percentage of defective components produces by each company is 4%, 5% and 14% for X, Y and Z, respectively. What is the probability that a given defective component came from Company Y?

Please enter your answer as a decimal with 3 significant digits, e.g., .250 or 0.250.

Discuss the advantages and disadvantages of using R to analyze data compared to a spreadsheet tool such as Microsoft Excel or Tableau. Provide specific examples to illustrate your ideas.

1. What is the median of the sample of size​ 30?

2.For each data set recalculate the mean and​ median, assuming that the individual whose IQ is 108, and108 is accidently recorded as 180. What is the median of the new sample of size​ 30?

1. A grocery store counts the number of customers who arrive during an hour. The average over a year is 29 customers per hour. Assume the arrival of customers follows a Poisson distribution. (It usually does.) Find the probability that at least one customer arrives in a particular one minute period. Round your answer to 3 decimals. Find the probability that at least two customers arrive in a particular 2 minute period.

2. Label each as one of the following

Exponential

Poisson

Binomial

Uniform

1. a constant probability density and charts as a rectangle
2. fixed number of trials with only 2 possible outcomes and the trials are independent  
3. models the time until some specifi event occurs such as equipment failure  
4. events happen with a known average rate and independently of the time since the last event  

An email system sends incoming mail to either the In-Folder (I) or the Trash Folder (T). You classify incoming mail as Useful (U), in which case you want it sent to I, or as a Nuisance (N) in which case you would like it sent to T. If incoming mail is U, the system sends it to T with probability 0.1. If the incoming mail is N, the system sends it to I with probability 0.05. Suppose a proportion 0.35 of your incoming mail is N.

What is the probability that an incoming mail is sent to T?

What is the probability that an incoming mail is U given that it is sent to T?

One of the quirks of the ground is occasional acid fog. Only 150 grounders are immune to acid fog out of a total of 3000 grounders. For a random group of 250 grounders in an acid fog;

A. (6 points) What is the expected value and standard deviation of the number of survivors? (HINT: It might be useful to think about the Binomial distribution here.) (Your answer here)

B. (8 points) what is the approximate probability that the number of survivors is at least 20? (Your answer here)

C. (6 points) Verify the conditions needed to compute the probability in Part (B) above. (Your answer here)

QUESTION 4

1. You gather data from 28 parolees who are currently enrolled in job training programs while on parole. You find that over the past year, they have been cited an average of 3.2 times for technical parole violations with a standard deviation of 1.2.

   Using this information, construct a 99% confidence interval for the overall mean technical violation rate for parolees who are enrolled in job training programs. Round all answers to 2 decimal points (0.00). Be sure to interpret your results.

he weight of an organ in adult males has a​ bell-shaped distribution with a mean of 320 grams and a standard deviation of 45 grams. Use the empirical rule to determine the following. ​

(a) About 99.7​% of organs will be between what​ weights?

​(b) What percentage of organs weighs between 230 grams and 410 ​grams? ​

(c) What percentage of organs weighs less than 230 grams or more than 410 ​grams? ​

(d) What percentage of organs weighs between 275 grams and 455 ​grams?