Identify which type of sampling is used. A school wants to survey student opinions on a new school policy, but they want to ensure that different grades are represented in the sample. They could divide students into strata (grades) and then randomly sample students from each grade.

Identify which type of sampling is used. A school wants to survey student opinions on a new school policy. They have a list of all students (the population). They assign each student a number, generate random numbers, and select students whose numbers match the generated random numbers.

A Washington DC tour company gives tours all year and offers a Weekend tour and a 7-Day tour. The table below shows the number of customers by season and by length of tour.   Spring Summer Winter Fall Total Weekend 68 194 97 46 405 7-Day 18 52 40 15 125 Total 86 246 137 61 530 Answer the following and present your answer as a proportion rounded to 3 decimals.  example 61/530 = .115 or 0.115. A.  Find the Joint probability for customers who book a weekend tour in the winter. [response1] B. Find the marginal probability that customers book a 7 day tour in the summer. [response2] C. What is the probability that a customer books a weekend tour given it is spring?  [response3]    

For a statistics project a student gathered data on monthly car insurance premiums paid by students and faculty at a California community college in 2008. She found a fairly strong linear relationship between driving experience and monthly car insurance premiums. She used the line shown in the scatterplot to summarize the pattern in the data. Here is the equation of the line: y = -1.45x + 97  The predicted monthly car insurance premium paid by someone who has been driving 12 years is ________ dollars a month.

Researchers at the University of Wisconsin at Madison conducted an experiment to study the effect of meditation on the immune system. The researchers randomly assigned volunteers to one of two treatments. One group completed an 8-week course in meditation and actively practiced meditation during this period. The other group received no meditation training and did not meditate during the 8-week period. At the end of the experiment researchers gave the subjects a flu shot. A healthy immune system will produce antibodies in response to a vaccine. At 4-weeks and 8-weeks after the flu shot, researchers did a blood test to measure the levels of antibodies produced against the vaccine. Both groups had an increased level of antibodies, but the meditators had a significantly greater increase in antibodies than the non-meditators. Psychosomatic Medicine published the results in 2003 in an article titled “Alterations in Brain and Immune Function Produced by Mindfulness Meditation.” Which of the following is NOT part of the experiment design?

  I am interested in finding out how much time the typical college student spends on Snapchat. How should I collect my data?     a.  Select a sample from the population of college students.   b.  Select a population from the sample of college students.   c.  Conduct a census of all college students.   d.  None of the above

The residual is the difference between the ________ and the ________.

How many grams of N2 are produced from 100. g of NH3 in the following reaction? 4NH3(g) + 6NO(g) → 5N2(g) + 6H2O(l)

At STP, what is the mass of 11.2 liters of O2 gas?

When 3.05 moles of CH4 are mixed with 5.03 moles of O2 the limiting reactant is CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)