A local Starbucks coffee shop has two baristas filling orders, and it is known that the time it takes for each barista to complete an order is exponentially distributed with average 60 seconds. You are next in line with barista 1 filling an order for John and barista 2 filling an order for Mary. When one of these two customers gets their order, you will proceed to that barista to get your order filled. What is the probability that, of these three customers, you will be the last one of the three to leave the coffee shop with your coffee order?

Chapter 13

13.1 Jean tests the effects of four different levels of caffeine (no caffeine, 40mg caffeine, 80mg caffeine, 120mg caffeine) on public speaking ability. One group of participants was tested in all four conditions over the course of four weeks – a different condition each week. What statistical analysis should Jean conduct to determine the effect of caffeine on public speaking?

13.2 How does the formula for the repeated-measures ANOVA differ from the formula for the One-way, independent-measures ANOVA?

13.3 Calculate SS_{between subjects} for the following data set. SHOW WORK

Person   Treatment 1       Treatment 2       Treatment 3

A       8           5           7

B       10           4           5

C       6           4           4

D       8           3           6

E       7           6           5

F       8           4           5

13.4 What three hypothesis tests do you have to conduct if you are using a Two-Factor (Factorial) ANOVA to analyze your data? (list/describe each one)

13.5 You can do some basic calculations based on treatment means, to get an idea of what types of effects might be present in a factorial study (even if you can’t say if they are statistically significant). Based on the table of means below, does it look like there could be any main effects or interactions? Specify which ones. SHOW WORK

Use the following scenario and data to answer questions 13.6 - 13.7

Researchers are interested in how serving temperature and pouring method affect the taste of Champagne (more bubbles = better taste). In this 3x2 factorial design, different glasses of Champagne are poured under different conditions; the summary data for the study appear in the table below. The researchers want to know which method is best.

n = 10

N = 60

∑X² = 1150

*Note, low averages mean few bubbles = Champagne is less tasty

13.6 Work through the steps involved in calculating this Factorial ANOVA for the Champagne study. Fill out the ANOVA table below as you go through the steps. Show work for Full Credit and the chance of Partial Credit.

Source               SS           df       MS       F

Between treatments

   Temperature

   Pour

Temperature X Pour

Within treatments

Total

13.7 What critical F value would you use to evaluate the three hypotheses in the Champagne ANOVA?

Temperature critical F =

Pour critical F =

Temperature X Pour critical F =

Chapter 14

14.1 The figure on the right is a scatterplot showing the relationship between drive ratio and horsepower. Based only on the figure, how would you describe this relationship? (Make sure to address its form, direction, and strength.)

Form –

Direction –

Strength –

14.2 What is the biggest limitation a researcher faces when using a correlational design?

14.3 Give one example of a study that would need to use a correlational design?

End of Lab 10!

You just started your first full time job out of college. You recall from your finance course the importance of starting to save early for retirement. You plan on making deposits of $215 per pay check into a stock account and $130 per pay check into a bond account. You are paid every two weeks (26 pay checks per year). It is your plan to make these deposits for the next thirty-years. You expect that you will earn 8.75% per year on the stock account and 5.5% on the bond account. When you retire in thirty-years you plan on depositing the balance the money into a money-market account that you expect should pay 2%. How much could you withdraw monthly, and have the money last for the next thirty years?

You just started your first full time job out of college. You recall from your finance course the importance of starting to save early for retirement. You plan on making deposits of $215 per pay check into a stock account and $130 per pay check into a bond account. You are paid every two weeks (26 pay checks per year). It is your plan to make these deposits for the next thirty-years. You expect that you will earn 8.75% per year on the stock account and 5.5% on the bond account. When you retire in thirty-years you plan on depositing the balance the money into a money-market account that you expect should pay 2%. How much could you withdraw monthly, and have the money last for the next thirty years?

The article "Plugged In, but Tuned Out"† summarizes data from two surveys of kids age 8 to 18. One survey was conducted in 1999 and the other was conducted in 2009. Data on number of hours per day spent using electronic media that are consistent with summary quantities given in the article are given below (the actual sample sizes for the two surveys were much larger). For purposes of this exercise, assume that it is reasonable to regard the two samples as representative of kids age 8 to 18 in each of the 2 years that the surveys were conducted.
2009   5   9   5   8   7   6   7   9   7   9   6   9   10   9   8
1999   4   5   7   7   5   7   5   6   5   6   7   8   5   6   6

(a)
Because the given sample sizes are small, in order for the two-sample t test to be appropriate, what assumption must be made about the distributions of electronic media use times?
o We need to assume that the population distribution in 1999 of time per day using electronic media are normal.
o We need to assume that the population distribution in 2009 of time per day using electronic media are normal.
o We need to assume that the population distributions in both 1999 and 2009 of time per day using electronic media are normal.
o We need to assume that the population distribution in either 1999 or 2009 of time per day using electronic media is normal.

Use the given data to construct graphical displays that would be useful in determining whether this assumption is reasonable. Do you think it is reasonable to use these data to carry out a two-sample t test?
o The boxplot of the 2009 data is roughly symmetrical with no outliers, so the assumption is reasonable.
o Both the boxplot of the 1999 data and the 2009 data are skewed to the right, so the assumption is not reasonable.
o The boxplot of the 1999 data is roughly symmetrical with no outliers, so the assumption is reasonable.
o Boxplots of the both the 1999 data and 2009 data are roughly symmetrical with no outliers, so the assumption is reasonable.
o The boxplot of the 1999 data has an outlier to the far right, so the assumption is not reasonable.

(b)
Do the given data provide convincing evidence that the mean number of hours per day spent using electronic media was greater in 2009 than in 1999? Test the relevant hypotheses using a significance level of 0.01. (Use a statistical computer package to calculate the P-value. Use μ2009 − μ1999. Round your test statistic to two decimal places, your df down to the nearest whole number, and your P-value to three decimal places.)
t   =  
df   =  
P-value   =  

State your conclusion.
o Reject H0. There is convincing evidence that the mean number of hours per day spent using electronic media was greater in 2009 than in 1999.
o Fail to reject H0. There is convincing evidence that the mean number of hours per day spent using electronic media was greater in 2009 than in 1999.
o Fail to reject H0. There is not convincing evidence that the mean number of hours per day spent using electronic media was greater in 2009 than in 1999.
o Reject H0. There is not convincing evidence that the mean number of hours per day spent using electronic media was greater in 2009 than in 1999.

(c)
Construct and interpret a 98% confidence interval estimate of the difference between the mean number of hours per day spent using electronic media in 2009 and 1999. (Use μ2009 − μ1999. Round your answers to two decimal places.)

_______ to _______ hours

Interpret the interval.
o We are 98% confident that the true difference in mean number of hours per day spent using electronic media in 2009 and 1999 is between these two values.
o We are 98% confident that the true mean number of hours per day spent using electronic media in 2009 is between these two values.
o We are 98% confident that the true mean number of hours per day spent using electronic media in 1999 is between these two values.
o There is a 98% chance that the true mean number of hours per day spent using electronic media in 2009 is directly in the middle of these two values.
o There is a 98% chance that the true difference in mean number of hours per day spent using electronic media in 2009 and 1999 is directly in the middle of these two values.

(everything bold needs an answer)

Here is your assigned case problem: A 34-year-old woman came to the physician with a 2-month history of increasing weakness, persistent nonproductive cough, fever and chills accompanied by night sweats, and a 13-pound weight loss over a 6-month period. Results of chest radiographs and purified protein derivative test (for tuberculosis) were negative. The patient was treated with ciprofloxacin and her cough improved, but she continued to grow weaker and was able to consume only small quantities of food. The patient appeared pale and cachectic. Tenderness and fullness were present in the left upper quadrant, and the spleen was palpable below the umbilicus. No hepatomegaly or peripheral adenopathy was noted.

Her laboratory results were as follows:

WBCs—248 x 10^9/L

HGB—9.5 g/dl

HCT—26.3%

Platelets—449 x10^9/L

Segmented neutrophils—44%

Band neutrophils—4%

Lymphocytes—10%

Eosinophils—3%

Basophils—7%

Myelocytes—30%

Promyelocytes—1%

Myeloblasts—1%

Nucleated RBCs—2 per 100

WBCs Reticulocytes—3%

Leukocyte alkaline phosphatase (LAP) score—20

(reference range, 40 to 130)

Lactate dehydrogenase—692 IU

(reference range, 140 to 280 IU)

Uric acid—8.1 mg/dL (reference range, 4 to 6 mg/dL)

Questions:

1. What is the significance of the elevated WBC count and abnormal WBC differential?

2. How does the LAP score aid in the diagnosis?

3. What is your diagnosis based on the presented case ?

An educational psychologist wants to know if length of time and type of training affect learning simple fractions. Fifth graders were randomly selected and assigned to different times (from 1 to 3 hours) and different teaching conditions (old method vs. meaningful method). All students were then tested on the "fractions" subtest of a standard arithmetic test. What can the psychologist conclude with an α of 0.05?

a) What is the appropriate test statistic?
---Select--- na one-way ANOVA within-subjects ANOVA two-way ANOVA

b) Input the appropriate value(s) to make a decision about H₀.
Train: p-value = ___________ ; Decision:  ---Select--- Reject H0 Fail to reject H0
Time: p-value =___________   ; Decision:  ---Select--- Reject H0 Fail to reject H0
Interaction: p-value =___________   ; Decision:  ---Select--- Reject H0 Fail to reject H0


c) Using the SPSS results, compute the corresponding effect size(s) and indicate magnitude(s).
Train: η² =___________   ;  ---Select--- na trivial effect small effect medium effect large effect
Time: η² =  ___________ ;  ---Select--- na trivial effect small effect medium effect large effect
Interaction: η² =___________   ;  ---Select--- na trivial effect small effect medium effect large effect


d) Make an interpretation based on the results.

1)There is a training difference in learning fractions.

2)There is no training difference in learning factions.    

1)There is a time difference in learning fractions.

2)There is no time difference in learning fraction.    

1)There is a training by time interaction in learning fractions.

2)There is no training by time interaction in learning fractions.   

Pepper’s Products manufactures and sells two types of chew toys for pets, Squeaky and Silent. In May, Pepper’s Products had the following costs and revenues: Pepper's Products Income Statement For the Month of May Squeaky Silent Total Sales revenue $ 149,000 $ 170,000 $ 319,000 Direct materials 19,000 22,000 41,000 Direct labor 80,000 20,000 100,000 Overhead costs Administration 20,000 Production setup 45,000 Quality control 15,000 Distribution 20,000 Operating profit $ 78,000 Pepper’s Products currently uses labor costs to allocate all overhead but is considering implementing an activity-based costing system. After interviewing the sales and production staff, management decides to allocate administrative costs on the basis of direct labor costs but to use the following bases to allocate the remaining overhead: Activity Level Activity Cost Driver Squeaky Silent Setting up Number of production runs 10 20 Performing quality control Number of inspections 30 30 Distribution Number of units shipped 80,000 120,000 Required: a. Complete the income statement using the preceding activity bases. (Do not round intermediate calculations.) c. Restate the income statement for Pepper's Products using direct labor costs as the only overhead allocation base. (Do not round intermediate calculations.)

Is the crime rate in New York different from the crime rate in New Jersey? Independent random samples from region A (cities in New York) and region B (cities in New Jersey) gave the following information about violent crime rate (number of violent crimes per 100,000 population). (Reference: U.S. Department of Justice, Federal Bureau of Investigation.)

Use a 10% level of significance to test the claim that there is no difference in the crime rate distributions of the two states.

Find the P-value of the sample test statistic. (Use 4 decimal places.)

The following data represent annual percentage returns on Vanguard Total Bond Index for a sequence of recent years. This fund represents nearly all publicly traded U.S. bonds. (Reference: Morningstar Mutual Fund Analysis.)

Test the sequence for randomness about the median. Use α = 0.05.

Find the sample test statistic R, the number of runs.

1. Write a class Volume that stores the volume for a stereo that has a value between 0 and 11. Usage of the class is listed below the problem descriptions. Throughout the class you must guarantee that:
   1. The numeric value of the Volume is set to a number between 0 and 11. Any attempt to set the value to greater than 11 will set it to 11 instead, any attempt to set a negative value will instead set it to 0.
   2. This applies to the following methods below: __init__, set, up, down

You must write the following methods:

3. __init__ - constructor.   Construct a Volume that is set to a given numeric value, or, if no number given, defaults the value to 0.   (Subject to 0 <= vol <=11 constraint above.)
4. __repr__ - converts Volume to a str for display, see runs below.
5. set – sets the volume to the specified argument (Subject to 0 <= vol <=11 constraint above.)
6. get – returns the numeric value of the Volume
7. up – given a numeric amount, increases the Volume by that amount. (Subject to 0 <= vol <=11 constraint above.)
8. down – given a numeric amount, decreases the Volume by that amount. (Subject to 0 <= vol <=11 constraint above.)
1. __eq__ - implements the operator ==.   Returns True if the two Volumes have the same value and False otherwise.

use python 3.7