Another student must pass through 12 sets of traffic lights on his way to university each day. Suppose
that each of the lights is green 36% of the time, yellow 5% of the time, and red 59% of the time.
Suppose it is known that the traffic lights function independently.
(a) What is the probability that the student encounters exactly five red lights on his way to university
one day?
(b) What is the probability that the student encounters at least three green lights on his way to
university one day?
(c) In a five-day school week, what is the probability that the student encounters exactly seven yellow
lights on his way to university?
In: Statistics and Probability
A study of hospital admissions in New York State found that of the admissions led to treatment-caused injuries. One-seventh of these treatment-caused injuries resulted in death, and one-fourth were caused by negligence. Malpractice claims were filed in one out of cases involving negligence, and payments were made in one out of every two claims.
a. What is the probability a person admitted to the hospital will suffer a treatment-caused injury due to negligence (to 2 decimals)?
b. What is the probability a person admitted to the hospital will die from a treatment caused injury (to 3 decimals)?
c. In the case of a negligent treatment-caused injury, what is the probability a malpractice claim will be paid(to 5 decimals)?
In: Statistics and Probability
An oil company purchased an option on land in Alaska. Preliminary geologic studies assigned the following prior probabilities.
a. What is the probability of finding oil (to 1 decimal)?
b. After feet of drilling on the first well, a soil test is taken. The probabilities of finding the particular type of soil identified by the test are given below.
Given the soil found in the test, use Bayes' theorem to compute the following revised probabilities (to 4 decimals).
What is the new probability of finding oil (to 4 decimals)?
According to the revised probabilities, what is the quality of oil that is most likely to be found?
- Select your answer -High qualityMedium qualityNo oil
In: Statistics and Probability
A sample of 45 entrepreneurs worked an average of 52 hours a week. The population is approximately normally distributed with a standard deviation of 20 hours per week. You want to test whether there is sufficient evidence at the α = 0.10 significance level that entrepreneurs work more than 48 hours per week.
(a) Define the parameter to be tested.
(b) What is the null hypothesis (H0)? What is the alternative hypothesis (H1)?
(c) Specify the test statistic and identify its (approximate) distribution if H0 is true.
(d) Compute the observed value of the test statistic.
(e) Compute the p-value.
(f) Report the strength of the evidence against H0 in favour of H1.
(g) Report the estimated value of the parameter along with the estimated standard error.
(h) If we are asked to test H0 at the significance level α, compare α with the p-value and reject H0 exactly when the p-value ≤ α. Explain your decision in terms of the number of hours worked per week by entrepreneurs.
In: Statistics and Probability
How do you interpret the unstandardized regression coefficient for a predictor variable? If the regression coefficient for a predictor variable is .52, what does that mean? If the regression coefficient for a predictor variable is -.47, what does that mean?
In: Statistics and Probability
In the last few years, many research studies have shown that the purported benefits of hormone replacement therapy (HRT) do not exist, and in fact, that hormone replacement therapy actually increases the risk of several serious diseases. A four-year experiment involving 4432 women was conducted at 33 medical centres. Half of the women took placebos and half took a prescription drug, a widely prescribed type of hormone replacement therapy. There were
x1 = 48
cases of dementia in the hormone group and
x2 = 20
in the placebo group. Is there sufficient evidence to indicate
that the risk of dementia is higher for patients using the
prescription drug? Test at the 1% level of significance. (Round
your answers to two decimal places.)
1-2. Null and alternative hypotheses:
H0: (p1 − p2) = 0 versus Ha: (p1 − p2) < 0H0: (p1 − p2) = 0 versus Ha: (p1 − p2) ≠ 0 H0: (p1 − p2) ≠ 0 versus Ha: (p1 − p2) = 0H0: (p1 − p2) < 0 versus Ha: (p1 − p2) > 0H0: (p1 − p2) = 0 versus Ha: (p1 − p2) > 0
3. Test statistic: z =
4. Rejection region: If the test is one-tailed, enter
NONE for the unused region.
z >
z <
5. Conclusion:
H0 is not rejected. There is sufficient evidence to indicate that the risk of dementia is higher for patients using the prescription drug.H0 is rejected. There is sufficient evidence to indicate that the risk of dementia is higher for patients using the prescription drug. H0 is not rejected. There is insufficient evidence to indicate that the risk of dementia is higher for patients using the prescription drug.H0 is rejected. There is insufficient evidence to indicate that the risk of dementia is higher for patients using the prescription drug.
In: Statistics and Probability
1. Chi-square Test of Independence
A political psychologist is interested in whether the community a person lives in is related to that person's opinion on an upcoming water conservation ballot initiative. The psychologist surveys a random sample of 96 people by phone from three different communities, with the results shown in the table below. At a 10% significance level, is there evidence that opinion on the water conservation ballot initiative depends on community membership?
Case Processing Summary |
||||||
Cases |
||||||
Valid |
Missing |
Total |
||||
N |
Percent |
N |
Percent |
N |
Percent |
|
Opinion * Community |
96 |
100.0% |
0 |
0.0% |
96 |
100.0% |
Opinion * Community Crosstabulation |
||||||
Community |
Total |
|||||
A |
B |
C |
||||
Opinion |
Against |
Count |
18 |
7 |
15 |
40 |
Expected Count |
17.5 |
9.2 |
13.3 |
40.0 |
||
For |
Count |
12 |
6 |
5 |
23 |
|
Expected Count |
10.1 |
5.3 |
7.7 |
23.0 |
||
NoOpinion |
Count |
12 |
9 |
12 |
33 |
|
Expected Count |
14.4 |
7.6 |
11.0 |
33.0 |
||
Total |
Count |
42 |
22 |
32 |
96 |
|
Expected Count |
42.0 |
22.0 |
32.0 |
96.0 |
Chi-Square Tests |
|||
Value |
df |
Asymptotic Significance (2-sided) |
|
Pearson Chi-Square |
2.912a |
4 |
.573 |
Likelihood Ratio |
3.061 |
4 |
.548 |
N of Valid Cases |
96 |
||
|
a. Type in the hypotheses. Please make sure to incorporate the problem context (i.e., do not write X and Y).
b. Type in the test statistic found from the SPSS. This is the value listed in the “Pearson Chi- Square” row under the “Value” column.
c. Type in the p-value found from the SPSS output. This is the value listed in the “Pearson Chi- Square” row under the “Asymptotic Significance (2-sided)” column.
d. Type your decision regarding the null hypothesis. e. Type in your conclusion using the context and units from the problem.
In: Statistics and Probability
Ten randomly selected people took an IQ test A, and next day they took a very similar IQ test B. Their scores are shown in the table below.
Person | A | B | C | D | E | F | G | H | I | J |
Test A | 99 | 86 | 112 | 90 | 106 | 78 | 120 | 95 | 118 | 101 |
Test B | 102 | 86 | 109 | 92 | 104 | 79 | 121 | 97 | 115 | 106 |
1. Consider (Test A - Test B). Use a 0.01 significance level to
test the claim that people do better on the second test than they
do on the first. (Note: You may wish to use software.)
(a) What test method should be used?
A. Matched Pairs
B. Two Sample z
C. Two Sample t
(b) The test statistic is
(c) The critical value is
(d) Is there sufficient evidence to support the claim that
people do better on the second test?
A. No
B. Yes
2. Construct a 99% confidence interval for the mean of the
differences. Again, use (Test A - Test B).
_____<μ<____
In: Statistics and Probability
Explain the influence of a level of significance and sample size has on hypothesis testing. Provide an example of the influence and how it impacts business decisions.
In: Statistics and Probability
(Please show work/step-by-step. Must be legible.)
1. The researcher from the Annenberg School of Communications is interested in studying the factors that influence how much time people spend talking on their smartphones. She believes that gender might be one factor that influences phone conversation time. She specifically hypothesizes that women and men spend different amounts of time talking on their phones. The researcher conducts a new study and obtains data from a random sample of adults from two groups identified as women and men. She finds that the average daily phone talking time among 15 women in her sample is 42 minutes (with a standard deviation of 6). The average daily minutes spent talking on the phone among 17 men in her sample is 38 (with a standard deviation of 5). She selects a 95% confidence level as appropriate to test the null hypothesis.
a) How many degrees of freedom are there?
b) What is the obtained value of the test statistic (t)?
c) What is the critical value of the test statistic (t)? [t-obtained]
d) What decision should the researcher make about the null hypothesis? Be sure to explain your answer (e.g., what numbers provide the basis for this decision?).
In: Statistics and Probability
You obtained the following data related to demographics in your statistics class:
Race Number of Students
Hispanic 15
Asian 10
African American 12
Caucasian 19
Native American 5
What can you infer from your data?
You obtained the following data related to demographics in your statistics class:
Religion Number of Students
Christian 17
Muslim 18
Buddhist 19
Catholics 20
Not Religious 24
What can you infer from your data?
A professor constructed a new personality test and wants to test its construct validity. She administers the test to her students and assesses the construct validity.
Person Construct validity
1 34
2 25
3 15
4 16
5 19
6 25
7 22
8 30
9 14
10 10
11 8
12 20
What can you infer from your data?
In a study of modeling, one group of 20 children saw an adult acting aggressively on videotape. Later each child was placed in a room where he or she was given the opportunity to behave aggressively toward a Bobo doll (a humanlike dummy). The researchers recorded the number of aggressive acts towards the Bobo doll by each child in a 15-minute period. Here are the results:
Number of Aggressive Acts:
25
23
23
23
22
22
21
21
21
21
21
19
19
19
19
18
18
17
17
10
What can you infer from the data?
In: Statistics and Probability
A technology student project group worked with a machine shop that employs a CNC lathe in the machining of a part produced for a heavy equipment manufacturer. Some summary statistics for a diameter on the part obtained from 25 samples of n=4 parts turned on the lathe are given below. The units are inches.
Sample x-bar R
1 1.18093 .0001
2 1.18085 .0002
3 1.18095 .0002
4 1.18063 .0008
5 1.18053 .0007
6 1.18053 .0005
7 1.18053 .0005
8 1.18195 .0001
9 1.18100 .0003
10 1.18095 .0001
55 Sum 11.80885 .0007
Find retrospective control limits for the values above (both means and ranges). What do the x-bar and R values indicate about the stability of the turning process?
In: Statistics and Probability
A technology student project group worked with a machine shop that employs a CNC lathe in the machining of a part produced for a heavy equipment manufacturer. Some summary statistics for a diameter on the part obtained from 25 samples of n=4 parts turned on the lathe are given below. The units are inches.
Sample x-bar R
1 1.18093 .0001
2 1.18085 .0002
3 1.18095 .0002
4 1.18063 .0008
5 1.18053 .0007
6 1.18053 .0005
7 1.18053 .0005
8 1.18195 .0001
9 1.18100 .0003
10 1.18095 .0001
55 Sum 11.80885 .0007
Find retrospective control limits for the values above (both means and ranges). What do the x-bar and R values indicate about the stability of the turning process
In: Statistics and Probability
Dean takes his boat out fishing every weekend. His current boat is still in okay condition, but he decides he’d like to buy a new one. He finds the boat of his dreams for $20,950. He does some research and finds that his credit union will give him a 5-year loan with an APR of 4.25% if he makes a down payment of 18%.
Sam, Dean’s younger brother, tries to convince Dean to save up for a new boat instead of getting a loan. He tells Dean that the credit union has a savings account option that offers an APR of 1.2% compounded monthly, so long as the account maintains a minimum balance of $2000.
@ Write several paragraphs discussing the advantages and disadvantages of both methods for Dean. Explain the reasons a person might choose to finance a purchase and the reasons that a person might choose to save up for a purchase. If you were in Dean’s position, what would you do and why? Be sure to use your work and answers from the proceeding questions to support your explanations and assertions.
I really need the last part. Please, write at least three paragraphs and your own words in detail question.
THANKS.
In: Statistics and Probability
We are creating a new card game with a new deck. Unlike
the normal deck that has 13 ranks (Ace through King) and 4 Suits
(hearts, diamonds, spades, and clubs), our deck will be made up of
the following.
Each card will have:
i) One rank from 1 to 15.
ii) One of 5 different suits.
Hence, there are 75 cards in the deck with 15 ranks for each of the
5 different suits, and none of the cards will be face cards! So, a
card rank 11 would just have an 11 on it. Hence, there is no
discussion of "royal" anything since there won't be any cards that
are "royalty" like King or Queen, and no face cards!
The game is played by dealing each player 5 cards from the deck.
Our goal is to determine which hands would beat other hands using
probability. Obviously the hands that are harder to get (i.e. are
more rare) should beat hands that are easier to get.
g) How many different ways are there to get a full house
(i.e. 3 of a kind and a pair, but not all 5 cards the same
rank)?
What is the probability of being dealt a full
house?
Round your answer to 7 decimal places.
h) How many different ways are there to get a straight
flush (cards go in consecutive order like 4, 5, 6, 7, 8 and all
have the same suit. Also, we are assuming there is no wrapping, so
you cannot have the ranks be 13, 14, 15, 1, 2)?
What is the probability of being dealt a straight
flush?
Round your answer to 7 decimal places.
In: Statistics and Probability