A professor states that in the United States the proportion of college students who own iPhones is .66. She then splits the class into two groups: Group 1 with students whose last name begins with A-K and Group 2 with students whose last name begins with L-Z. She then asks each group to count how many in that group own iPhones and to calculate the group proportion of iPhone ownership. For Group 1 the proportion is p1 and for Group 2 the proportion is p2. To calculate the proportion you take the number of iPhone owners and divide by the total number of students in the group. You will get a number between 0 and 1.

• What would you expect p1 and p2 to be?
• Do you expect either of these proportions to be vastly different from the population proportion of .66?
• Would you be surprised if p1 was different than p2?
• Would you be surprised if they were the same or similar?
• What statistical concept describes the relationship between the first letter of someone's last name and whether or not they own an iPhone?

Problem: Susan Sound predicts that students will learn most effectively with a constant background sound, as opposed to an unpredictable sound or no sound at all. She randomly divides twenty-four students into three groups of eight. All students study a passage of text for 30 minutes. Those in group 1 study with background sound at a constant volume in the background. Those in group 2 study with noise that changes volume periodically. Those in group 3 study with no sound at all. After studying, all students take a 10 point multiple choice test over the material. Their scores follow:
group test scores

1) constant sound 7 4 6 8 6 6 2 9
2) random sound 5 5 3 4 4 7 2 2
3) no sound 2 4 7 1 2 1 5 5

Please give me step by step how to answer the question.

A professor of business at a local college wanted to determine which of his two methods of teaching statistics resulted in better grades. He randomly selected 30 students from his current classes and set up two special sub-sections of the course, one for each of his two methods, with 15 students in each sub-section. After the semester was over, he placed the final averages for each of the students in a spreadsheet and wanted to determine if the difference in the average scores of the samples indicated that there would be a difference in the scores of the population of students.

Use the correct Excel function found in Data Analysis to determine if the population average scores of the two methods are the same. At the bottom of the Excel worksheet, write a Decision Rule and Conclusion Statement

Method 1: 86, 69, 85, 68, 68, 68, 87, 85, 85, 72, 67, 73, 84, 66, 76

Method 2: 91, 94, 55, 96, 70, 91, 58, 87, 64, 87, 95, 65, 86, 75, 88

Students attending a certain university can select from 130 major areas of study. A student's major is identified in the registrar's records with a two-or three-letter code (for example, statistics majors are identified by STA, math majors by MS). Some students opt for a double major and complete the requirements for both of the major areas before graduation. The registrar was asked to consider assigning these double majors a distinct two- or three-letter code so that they could be identified through the student records system.

(a)

What is the maximum number of possible double majors available to the university's students?

double majors

(b)

If any two- or three-letter code is available to identify majors or double majors, how many major codes are available?

codes

(c)

How many major codes are required to identify students who have either a single major or a double major?

codes

(d)

Are there enough major codes available to identify all single and double majors at the university?

Yes

No    

Please answer (b) questions 1 and 2

Joyful Journeys Music School provides private music lessons for elementary students. Its operating costs are as follows:

Rent on facilities         $2,200 per month

                        Advertising                    $274 per month

                        Instrument Rent             $750 per month

                        Teaching Instruction      $40 per student

                        Books                               $5 per student

                        Other Costs                      $3 per student

Joyful Journeys charges $100 per student per month.

(a)        Determine the company’s break-even point in (1) number of students taught per month and (2) dollars.

(b)        Joyful Journeys has just received notice that the rent on their facilities will be increasing by $500 per month and the instrument rent will also be increasing $20 per month.

(1) Determine the company’s break-even point in the number of students taught per month based on the new information.  

(2) Determine the amount to charge per student if Joyful Journeys does not increase the number of students taught.

a. By hand, make an ordered stemplot of the distribution of the variable MothersAge for the female students. Show both your rough and final version of the stemplot. Use stems of five (See the Notes for an explanation of what stems of five are). There are 63 female students.

Mother's age 18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,51

Female 1, 0, 2, 2, 3, 4, 7, 3, 2, 4, 7, 1, 6, 4, 5, 3, 1, 4, 0, 1, 1, 1, 0, 1, 0

Use the stem and leaf plots that you previously created to help you draw and label histograms on your scratch paper with bin width of 2 for mothers's age at birth of female students and for mother's age at birth of male students. Make the lower bound of your first bin 16.

Comment: Bin width of 2 is not a typo. Yes, your stem and leaf plot has bins of 5 so some thinking is required, but at least your stem and leaf plot has the values in order for you.

Question 10:

The distribution of the amount of money spent by students on textbooks in a semester is approximately normal in shape with a mean of 494 and a standard deviation of 39.

According to the standard deviation rule, approximately 68% of the students spent between $_____ and $ ______ on textbooks in a semester.

Question 11:

The distribution of IQ (Intelligence Quotient) is approximately normal in shape with a mean of 100 and a standard deviation of 16.

According to the standard deviation rule, _____ % of people have an IQ between 52 and 148. Do not round.

Question 12:

The distribution of IQ (Intelligence Quotient) is approximately normal in shape with a mean of 100 and a standard deviation of 19.

According to the standard deviation rule, only ______ % of people have an IQ over 157.

Question 13:

The distribution of the amount of money spent by students on textbooks in a semester is approximately normal in shape with a mean of: μ= 429 and a standard deviation of: σ= 23.

According to the standard deviation rule, almost 16% of the students spent more than what amount of money on textbooks in a semester?

The accompanying data represent the pulse rates​ (beats per​ minute) of nine students. Treat the nine students as a population. Compute the​ z-scores for all the students. Compute the mean and standard deviation of these​ z-scores. Compute the​ z-scores for all the students. Complete the table.

Student 1 .

Student 2

Student 3

Student 4

Student 5

Student6

Student 7

Student 8

Student 9

​(Round to the nearest hundredth as​ needed.) Compute the mean of these​ z-scores.

The mean of the​ z-scores is _____

. ​(Round to the nearest tenth as​ needed.)

Compute the standard deviation of these​ z-scores. The standard deviation of the​ z-scores is ____

. ​(Round to the nearest tenth as​ needed.) Enter your answer in each of the answer boxes.

Pulse Rates Student Pulse

Student 1    77

Student 2    61

Student 3    60

Student 4    80

Student 5    73

Student 6    80

Student 7 80

Student 8    68

Student 9    73

1. A telephone company claims that less than 15% of all college students have their own cell phone plan. A random sample of 70 students revealed that 8 of them had their own plan. Test the company's claim at the 0.05 level of significance.

2. A college statistics instructor claims that the mean age of college statistics students at a local Dallas-based institution is 23. A random sample of 35 college statistics students revealed a mean age of 25.1. The population standard deviation is known to be 4.1 years. Test his claim at the 0.1 level of significance.

3. A random sample of 85 adults ages 18-24 showed that 11 had donated blood within the past year, while a random sample of 254 adults who were at least 25 years old had 18 people who had donated blood within the past year. At the 0.05 level of significance, test the claim that the proportion of blood donors is not equal for these two age groups.

Generally, schools in the United States are organized around four goals: Academic, Civic, Personal, and Vocational. The academic goals are the knowledge and curriculum that we expect students to learn in school (English, math, science, etc). With the civic goals we want our students to learn about the American system of government and to learn the skills and attitudes to become informed citizens (courses such as American government, social studies, political science). The personal goals help our students with issues such as development of personal talents (think music, drama, athletics, etc.), life skills (maintaining a bank account, economics, consumer information) and health (PE, health classes, biology). In the vocational goals, students learn skills and knowledge which will make them productive in the workplace; able to leave school and to participate in the job market.

Question: Based on this information, which goal or goals do you think are most important for our schools. Which goals should American schools concentrate on? Explain your answers.