The table below gives the age and bone density for five randomly selected women. Using this data, consider the equation of the regression line, yˆ=b0+b1xy^=b0+b1x, for predicting a woman's bone density based on her age. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant.
Age | 4646 | 4848 | 5757 | 5959 | 6868 |
---|---|---|---|---|---|
Bone Density | 353353 | 344344 | 322322 | 320320 | 314314 |
Table
Copy Data
Step 1 of 6 :
Find the estimated slope. Round your answer to three decimal places.
In: Statistics and Probability
Harley's Daycare will run a promotional raffle that offers a chance to win either a lifetime discount on merchandises (which results in a $1,000 savings) or a 5-year limited discount on any party-goods (which results in a $100 savings).
Is this promotion worth it if the tickets cost $15? |
The promotion is not worth it. |
ONLY if you cannot answer F1, for partial credit (6 points) answer F2.
[F1 (13 points)] Some additional collected data is presented in the table below:
Enrollment Camp/DayCare |
Infants (I) |
Toddler (2-3Y) (T) |
PreK_K (K) |
|
ParentsOasis (PO) |
0 |
10 |
50 |
60 |
SunAndFun (SF) |
8 |
32 |
20 |
60 |
NoPlaceLikeHome (NH) |
10 |
20 |
40 |
70 |
18 |
62 |
110 |
190 |
Give the literal formula first (not with numbers) and then solve: “what is the probability of not being a Toddler?” |
P(not toddler) = P(infants) + P(pre k) = 9.47 + 57.89 = .6736----->67.4% |
Give the literal formula first (not with numbers) and then solve: “What is the probability of being an infant or toddler given that you are attending the NoPlaceLikeHome camp?” |
|
Give the literal formula first (not with numbers) and then solve: “what is the probability of being a Pre-K_K child attending ParentsOasis camp?” |
|
Give the literal formula first (not with numbers) and then solve: “What is the probability of being in the Toddler or PreK_K group and attending SunAndFun.” |
|
Is there any relationship between being a toddler and attending a specific Camp/Daycare? Explain based on “given” probabilities values. |
F2. Partial Credit. Answer to it ONLY if you cannot answer F1
Another survey examines the parent’s preference in having lunch provided by the SummerIsFun Co. or lunch brought from home, based on their children’s age. Some parents might not care, any possibility is OK.
Camp/Daycare Food (D) |
Home Food (H) |
||
Parent (Infant/Toddler) IT |
50 |
100 |
150 |
Parent (pre-K,K) PK |
85 |
65 |
150 |
135 |
165 |
300 |
a) Compute the Marginal Probabilities and the Joint Probabilities.
Joint probabilities: |
Marginal probabilities: |
P(D&IT) = 16.66% |
P(D) = 45% |
P(D&PK = 28.33% |
P(H) = 55% |
P(H&IT) = 33.33% |
P(IT) =50% |
P(H&PK) = 21.66% |
P(PK) = 50% |
b) Compute: P(IT|H), P(IT or D)
[G(28 points)]
Overall, the amount of days attended (per summer) is normally distributed around 35 days with a standard deviation of 4 days.
What’s the probability that the number of attended days will be above 28? |
|
What percentile does an attendance of 35 days rank at? |
|
What is the probability of attending between 33 and 39 days? |
|
The parents with children at or below the 10%ile of number of days attended need to bring an explanatory note. What will be the threshold of 10%? |
|
How likely (what is the probability) is it to have the number of days attended less than 30? |
|
Children that are in the top 15% of attendance will receive a ticket to see the DubbleCamp. What is the minimum number of days of attendance in order to receive such a ticket? |
|
If 49 children (49 = size of the sample) selected randomly attend the summer camp, what’s the likelihood that their mean number of attended days will be within 2 days of the population mean? |
In: Statistics and Probability
Do the seven steps for each word problem
Step 1: Establish null and alternate hypotheses
State the null and alternative hypothesis (as a sentence and formula).
Step 2: Calculate the degrees of freedom
Step 3: Calculate t critical using critical t – table
Step 4: Calculate the Sum of Square deviation (SSD)
Step 5: Calculate t obtained
Step 6: Specify the critical value and the obtained value on a t-distribution curve
Step 7: Decision and Conclusion
Write a clear and concise conclusion.
A Pullman local sports store is interested in consumer purchasing likelihood of WSU gear (1=not at all to 7=very much) before and after a win in football. A researcher picks 10 WSU students as the participants of the study. The data are shown below. Use alpha = .01 to see whether a win in football increases consumers’ likelihood of buying WSU gear.
After: 4 5 5 6 5 7 5 6 3 4
Before: 3 5 4 4 5 6 5 4 3 3
A marketing researcher has heard that when kids are anonymous, they'll take more candy. To test this hypothesis, she brings 6 kids into a specially-constructed Halloween Lab with two rooms. Each room is identically decorated and contains a decorated front porch, a front door, and a doorbell. Behind the door is a confederate who will answer the door and offer a bowl of candy. The two rooms differ only in their lighting conditions. One room is light; one room is dark, the latter presumably leading to greater anonymity. She says, ok kids, I want you to go into each room and interact with the person behind the door as you would normally interact during Halloween. Ring the doorbell, say trick or treat, and then take some candy. So, the kids do this and the researcher measures how many pieces of candy they take. The data are shown below. Do kids take more candy under conditions that make them feel anonymous? Use alpha = .10.
Light Room: 1 2 1 1 2 2
Dark Room: 2 2 3 4 4 3
In: Statistics and Probability
A toy company is concerned that its distribution strategy is not working. Sean Masterson, the marketing manager stated that one of the primary goals in the distribution of a particular toy is to keep the prices similar throughout all their distribution channels. To find out if their strategy is failing, the marketing department took a survey of 5 different outlets in three different channels. The price results are in the following table:
Store |
Web sales |
Discount stores |
Department stores |
1 |
13 |
15 |
16 |
2 |
16 |
17 |
17 |
3 |
14 |
14 |
16 |
4 |
18 |
18 |
17 |
5 |
15 |
17 |
16 |
Using ANOVA, determine if there is a significant difference in prices between the three channels. Mr. Masterson wants to be 90% confident, so list all the steps of the hypothesis test and do the calculations then write a memorandum to Mr. Masterson stating your conclusion and backing it up with statistical analysis.
In: Statistics and Probability
The Harleys Daycare. decided to use 20 different water balloon categories. Their prices (on 100 units) are listed below:
27 25 10 7 13 20 27 15 25 10
22 16 11 9 12 20 17 17 23 20
a. Construct a grouped frequency distribution with 6 classes.
Step 1. Find Range
Step 2. Given the number of classes, the width of each class is
Step 3. Create class boundaries
Step 4. Find the numerical frequencies
b. Use Excel to construct a Histogram. (Tools à Data Analysis à Histogram à for the input range, select the given values, for the bin range select the classes upper boundaries values à check Chart Output)
Note: If you don’t have the capability of using excel for the histogram, draw one by hand.
[D(14 points)] Consider the following set of data containing the amount of paid tuition/week for part-timers:
Child Name |
Amount |
Z-Score |
Marie |
70 |
|
Philip |
80 |
|
John |
55 |
|
Isabela |
75 |
|
Raymond |
55 |
|
Richard |
75 |
|
Edgar |
80 |
|
Jerry |
85 |
|
Christiana |
60 |
|
Juliet |
85 |
Z = ( X – U)/ σ where u is the mean and σ is the standard deviation.
a. For the set of data given above, calculate the following descriptive statistics (Briefly explain, especially the quartiles calculations. Use the rules given in the homework 2). For the rest you can use excel tools as long as you show your work.
Mean |
2.71 |
Median |
2 |
Mode |
2 |
Who is in the lowest quartile? Explain |
Q1 = 1 Quartile 1 is the median of the lower half of the data. |
Who is in the uppermost quartile? |
Q3 = 5 Q3 is the median of the upper half of the data. |
Interquartile Range |
Interquartile range = q3 – q1 = 5 – 1 = |
Range |
Range = highest value – lowest value = 9 |
Standard Deviation |
2.49 |
Variance |
b. Compute the z-scores and enter them in the first given table. Give the formula you used.
c. What type of skewness does this data set have? The data set has a left tail skewness.
In: Statistics and Probability
Let (Un, U, n>1) be asequence of random variables such that Un and U are independent, Un is N(0, 1+1/n), and U is N(0,1), for each n≥1.
Calculate p(n)=P(|Un-U|<e), for all e>0.
Please give details as much as possible
In: Statistics and Probability
(PLEASE ANSWER BOTH QUESTIONS)
Think about the statistic you hear on TV... 4 out of 5 dentist prefer Trident gum over other brands. Is this true? Where did they come up with this? What if they only had a sample size of 200 dentists and all of those dentists in their sample were interviewed immediately after leaving a free promotional event sponsored by Trident? Would that seem legitimate to you?
This is a good example of how selecting a good, probability sample is needed to have valid results. You can use a convenient sample as was used in the example above. Give an example of how to choose 200 dentists using a good, probability sample.
In: Statistics and Probability
Convert the following binomial distribution problems to normal distribution problems. Use the correction for continuity.
a. P(x ≤ 16| n = 30 and p = .70)
b. P(10 < x ≤ 20)| n = 25 and p = .50)
c. P(x = 22| n = 40 and p = .60)
d. P(x > 14| n = 16 and p = .45)
In: Statistics and Probability
Of 12 possible building sites for factories, 5 have buried toxic waste sites that no one told
you about! If you choose 3 of the sites for initial building locations, what is the probability you
will be lucky enough to avoid any toxic waste sites?
In: Statistics and Probability
In: Statistics and Probability
Provide plots of the χ2(r) distributions (pdf) for values of r = 1,2,5,10,20.
In: Statistics and Probability
A study of reading comprehension in children compared three methods of instruction. The three methods of instruction are called Basal, DRTA, and Strategies. Basal is the traditional method of teaching, while DRTA and Strategies are two innovative methods based on similar theoretical considerations. The READING data set includes three response variables that the new methods were designed to improve. Analyze these variables using ANOVA methods. Be sure to include multiple comparisons or contrasts as needed. Write a report summarizing your findings.
Reading:
subject group pre1 pre2 post1 post2 post3 1 B 4 3 5 4 41 2 B 6 5 9 5 41 3 B 9 4 5 3 43 4 B 12 6 8 5 46 5 B 16 5 10 9 46 6 B 15 13 9 8 45 7 B 14 8 12 5 45 8 B 12 7 5 5 32 9 B 12 3 8 7 33 10 B 8 8 7 7 39 11 B 13 7 12 4 42 12 B 9 2 4 4 45 13 B 12 5 4 6 39 14 B 12 2 8 8 44 15 B 12 2 6 4 36 16 B 10 10 9 10 49 17 B 8 5 3 3 40 18 B 12 5 5 5 35 19 B 11 3 4 5 36 20 B 8 4 2 3 40 21 B 7 3 5 4 54 22 B 9 6 7 8 32 23 D 7 2 7 6 31 24 D 7 6 5 6 40 25 D 12 4 13 3 48 26 D 10 1 5 7 30 27 D 16 8 14 7 42 28 D 15 7 14 6 48 29 D 9 6 10 9 49 30 D 8 7 13 5 53 31 D 13 7 12 7 48 32 D 12 8 11 6 43 33 D 7 6 8 5 55 34 D 6 2 7 0 55 35 D 8 4 10 6 57 36 D 9 6 8 6 53 37 D 9 4 8 7 37 38 D 8 4 10 11 50 39 D 9 5 12 6 54 40 D 13 6 10 6 41 41 D 10 2 11 6 49 42 D 8 6 7 8 47 43 D 8 5 8 8 49 44 D 10 6 12 6 49 45 S 11 7 11 12 53 46 S 7 6 4 8 47 47 S 4 6 4 10 41 48 S 7 2 4 4 49 49 S 7 6 3 9 43 50 S 6 5 8 5 45 51 S 11 5 12 8 50 52 S 14 6 14 12 48 53 S 13 6 12 11 49 54 S 9 5 7 11 42 55 S 12 3 5 10 38 56 S 13 9 9 9 42 57 S 4 6 1 10 34 58 S 13 8 13 1 48 REALLY struggling with this thanks! 59 S 6 4 7 9 51 60 S 12 3 5 13 33 61 S 6 6 7 9 44 62 S 11 4 11 7 48 63 S 14 4 15 7 49 64 S 8 2 9 5 33 65 S 5 3 6 8 45 66 S 8 3 4 6 42
In: Statistics and Probability
The Binomial Distribution.
1. What makes the binomial distribution unique? What are its characteristics?
Give a real-world
example of a distribution of data that would be considered
binomial.
2. Solve the following problem:
About 30% of adults in United States have college degree.
(probability that a person has college degree is p = 0.30).
If N adults are randomly selected, find probabilities that
1) exactly X out of selected N adults have college degree
2) less than X out of selected N adults have college degree
3) greater than X out of selected N adults have college
degree
Choose your numbers for N and X.
In: Statistics and Probability
Student ID Age Gender
Nationality Married Children
Undergrad Major GMAT Score Previous
salary Monthly Expenses School Debt
1 30 Male US
No 0 Marketing 717
48100 1710 26580
2 32 Male US
No 0 Finance 658
62600 1870 0
3 32 Female US
No 0 Engineering
669 55500 1630 30560
4 30 Male India
No 0 Marketing 687
45600 1430 0
5 39 Male US
No 0 Marketing 633
59700 2020 25380
6 33 Male US
No 0 Other non-business
658 70000 2610 0
7 30 Female Europe
No 0 Other business
653 44500 1650 32370
8 35 Female US
No 0 Engineering
784 54000 1930 33240
9 37 Female Other
No 0 Engineering
40000 1640 64330
10 34 Male US
Yes 0 Finance
72100 2670 39950
11 32 Female US
No 0 Other business
784 42200 1130 9490
12 39 Male US
Yes 2 Other non-business
627 69300 2320 70780
13 33 Female US
Yes 1 Marketing 709
46100 2290 69360
14 26 Female US
No 0 Finance 757
53100 1820 12490
15 35 Male US
No 0 Finance 735
76400 1300 8840
16 35 Male US
No 0 Marketing
67500 2230 26330
17 33 Male US
No 1 Other non-business
686 67700 1770 48870
18 30 Male India
No 0 Marketing
46700 1370 22690
19 29 Female India
No 0 Marketing 749
46500 1530 20130
20 36 Female US
Yes 1 Engineering
736 73700 1970 31150
21 36 Male US
Yes 0 Finance 691
63400 1750 0
22 30 Male South
America No 0
Marketing 698 51900
2550 33910
23 39 Male India
No 0 Other non-business
743 63300 1750 29180
24 34 Male US
Yes 1 Engineering
710 63200 2130 53280
25 40 Male US
Yes 0 Other business
662 56200 2020 38560
26 30 Female South
America Yes 0
Finance 43300
1240 26400
27 33 Male US
Yes 1 Engineering
72200 1820 19450
28 32 Female India
Yes 2 Engineering
718 44300 2600 68260
29 34 Male US
No 0 Other non-business
716 59300 1620 0
30 40 Male China
No 0 Finance 711
69100 2270 30460
31 37 Male US
No 0 Engineering
76100 2430 0
32 28 Male US
No 0 Marketing 743
58800 1540 35420
33 28 Male US
No 0 Engineering
740 57200 1300 19180
34 27 Female US
No 0 Finance 695
45000 2100 72220
35 31 Female US
Yes 0 Other business
54200 1950 14640
36 35 Male US
Yes 1 Other business
69500 2390 38330
37 30 Male US
No 0 Engineering
765 77000 1450 16720
38 34 Female China
No 0 Finance 770
47900 1970 39250
39 33 Male US
Yes 1 Engineering
78900 1920 44820
40 34 Male US
No 0 Other business
726 62300 2210 23620
In: Statistics and Probability
Three perfectly logical men are told to stand in a straight line, one in front of the other. A hat is put on each of their heads. Each of these hats was selected from a group of five hats: two identical black hats and three identical white hats. None of the men can see the hat on his own head, and they can only see the person's hat in front of him. In how many distributions of the hats can the person in front deduce his own hat color?
In: Statistics and Probability