You wish to test the following claim (Ha) at a significance
level of α=0.001
Ho:μ=60.4
Ha:μ≠60.4
You believe the population is normally distributed, but you do not
know the standard deviation. You obtain the following sample of
data:
data |
---|
110.5 |
92 |
76.4 |
85.8 |
What is the test statistic for this sample? (Report answer accurate
to three decimal places.)
test statistic =
What is the p-value for this sample? (Report answer accurate to
four decimal places.)
p-value =
The p-value is...
This test statistic leads to a decision to...
As such, the final conclusion is that...
In: Statistics and Probability
In: Statistics and Probability
A fair red die and a fair green die are rolled.
(a) What is the probability that the sum of the numbers is even?
(b) What is the probability that the number on the red die is more than the number on the green die?
(c) What is the probability that the number on the red die is twice the number on the green die?
(d) What is the probability that the number on the red die is different from the number on the green die?
In: Statistics and Probability
A drug company is developing a new drug called Phantol that it hopes will provide relief to patients who suffer from respiratory infections. Phantol was given to a random sample of 450 patients who had upper respiratory infections and 365 of these patients experienced relief. The drug is marketable if more than 75% of patients experience relief while using Phantol. a) Using a 5% significance level, test the hypothesis that more than 75% of patients who suffer from upper respiratory infections experience relief when using Phantol. (4 points) b) Based on your conclusion what type of error might you be making? (Explain) (2 points) 7 Professor: David Wozniak Final Exam c) What is the 95% confidence interval for the proportion of patients who should experience relief using Phantol? (3 points) d) What sample size would you need to find a 95% confidence interval with a margin of error of 0.02? (Hint: is it likely that the p=0.5?
In: Statistics and Probability
Create your own confidence interval (you cannot use 80%, 95%, and 99%) and make sure to show your work.
using this sample data.
120, 124, 113, 97, 127, 96, 100, 121, 115, 109, 114, 109, 116, 110, 132, 104, 111, 104, 101, 107, 98, 135, 105, 109, 121, 107, 118, 109, 145, 98, 136, 117, 103, 118 126 129 121 105 100 120 107 120 121 99 106 109 127 114 105 102
In: Statistics and Probability
Decide and state whether a one-sample z test, a two- sample z test, or a t test is appropriate. Whichever test you choose, state your null hypothesis, then obtain a P -value and formulate a valid conclusion.
1a.) 20 subjects who do not speak German are asked to participate in a trial for a new type of crash course in the German language. 10 subjects are randomly placed in Group A, to test the new teaching method, while the other 10 are placed in group B and given a more traditional crash course in German (though they are not told this is not the new approach). After both courses have ended, evaluators (who don’t know which course each subject took) determine that 50% of subjects in Group A are competent speakers of German, compared to 40% of subjects in Group B. Based on this, does the new method work better, or is the 10% difference due to chance?
1b.) 200 subjects who do not speak German participate in a trial for a new type of crash course in the German language. 100 subjects are randomly placed in Group A, to experience the new teaching method, while the other 100 are placed in group B and given a more traditional crash course in German (though they are not told this is not the new approach). After both courses have ended, evaluators (who don’t know which course each subject took) determine that 42% of subjects in Group A are competent speakers of German, compared to 38% of subjects in Group B. Based on this, does the new method work better, or is the 4% difference merely due to chance?
In: Statistics and Probability
1. A population random variable X has mean LaTeX: \mu=10μ = 10 and standard deviation LaTeX: \sigma=5σ = 5. Samples of size 36 are drawn with replacement. Find the probability that the sample mean LaTeX: \overline{X}X ¯ will be between 6.5 and 14, inclusive?
2. 52 percent of the voting population of a city favor candidate A for mayor. What is the probability that more than 51 percent will favor A in a random sample 50 voters from the city?
In: Statistics and Probability
it is reported that the percentage of males 18 and older who have never been married is greater than the percentage of females 18 and over who have never been married. in a particular county, out of 50 males surveyed, 32% had never been married. while out of 40 females, 25% had never been married. conduct a hypothesis to determine if the proportion of men is greater than the proportion of women. let confidence level=0.05. use the p-value method.
In: Statistics and Probability
Homelessness and Illegal Substance Use
Illegal Drug Use |
No Use |
|
Homeless |
957 |
1248 |
Not Homeless |
2626 |
97203 |
For questions 1 and 2, your calculator will produce large numbers. To obtain instructions on how to interpret exponential output from a calculator, view this information sheet:
https://nnlm.gov/sites/default/files/nto/files/TOXNET/whatdoesEmeancalculator.pdf (Links to an external site.)Links to an external site.
In: Statistics and Probability
The following sample observations were randomly selected. (Do not round the intermediate values. Negative amount should be indicated by a minus sign. Round your answers to 3 decimal places.)
X: | 6 | 5 | 3 | 6 | 9 |
Y: | 4 | 6 | 5 | 1 | 12 |
Determine the 0.99 confidence interval for the mean predicted when x = 6.
Determine the 0.99 prediction interval for an individual predicted when x = 6.
In: Statistics and Probability
Let X be the number of heads and let Y be the number of tails in 6 flips of a fair coin. Show that E(X · Y ) 6= E(X)E(Y ).
In: Statistics and Probability
Please post all the work so I can understand the process! Thanks :)
Question 3:
The 9-month salaries at a daycare center are normally distributed with a mean of $18,000 and a standard deviation of $5,000.
a. |
What is the probability that an employee will have a salary between $15,520 and $18,480? |
b. |
What is the probability that an employee will have a salary more than $19,880? |
c. |
What is the probability that an employee will have a salary less than $28,440? |
In: Statistics and Probability
Flag this Question Question 11 What does the second column in a frequency table show? Group of answer choices
a)categories (or levels) of the variable
b)probability of the variable
c)frequencies
d)percentages
Flag this Question Question 122 pts A college instructor wants to know the amount of time her students spend on studying every day so she collected the information from everyone in her class. The data yielded a mean of 90 minutes and a standard deviation of 8 minutes. What is the variance?
Group of answer choices
64
8
2.
83
Question 132 pts
What is the standard deviation of the sample that consists of 3, 5, 9, 11, 15?
Group of answer choices
4.27
1.72
18.24
91.2
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Question 142 pts
You randomly select someone from a group of 20. Eight people in the group are females. What is the probability that the person you draw is a male?
Group of answer choices
.73
.60
.40
.12
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Question 152 pts
What minimum Z score does a student need to get to be ranked in the top 5% of her/his class? (Use the Z table)
Group of answer choices
around 2.33
around 1.28
around 1.65
around 0.05
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Question 162 pts
Explain why we make an inference about a population using a sample.
Group of answer choices
It is typically not possible or practcal to study the entire population of interest.
Samples are easier to analyze using mathematical analysis.
A sample is often vastly different of the population from which it is drawn.
We can's study a population of interest directly because it really does not exist.
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Question 172 pts
Meditation is proposed by some to improve the overall quality of sleep. A researcher wants to examine the effect of meditation on the number of minutes spent in deep sleep. She is not sure, however, if meditation will increase or decrease the number of minutes in deep sleep. Should she conduct a one-tailed or two-tailed hypothesis test, and why?
Group of answer choices
One-tailed because only one variable, sleep, is examined
One-tailed because meditation is proposed to improve sleep quality.
Two-tailed because there are two variables—whether or not people meditate and whether deep sleep is increased.
Two-tailed because the researcher is interested in any effect of meditation on deep sleep, increase or decrease.
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Question 182 pts
In a housing project there are 180 households in which English is usually spoken, 80 in which Spanish is usually spoken, and 40 in which the language is other than English or Spanish. A researcher approaches a house at random to conduct an interview. What is the chance that the usual language in that household will NOT be English?
Group of answer choices
.60
.33
.40
.12
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Question 192 pts
Interpret this statement: "We fail to reject the null hypothesis at alpha level of .05."
Group of answer choices
The probability was less than .05 that a sample like this could have been obained when the null hypothesis was true.
The probability was more than .05 that a sample like this could have been obtained when the null hypothesis was true.
The probability was less than .05 that a sample like this could have been obained when the null hypothesis was false.
The probability was more than .05 that a sample like this could have been obained when the null hypothesis was false.
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Question 202 pts
In a single throw of a die, what is the probability of attaining a number that is 2 or lower?
Group of answer choices
.67
.50
.20
.33
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Question 212 pts
What is a valid reason for choosing a two-tailed test even when a given direction can be predicted?
Group of answer choices
Statistical programs are set to default to two-tailed tests.
One-tailed tests are more effective in preventing Type I errors.
Two-tailed tests allow for the possibility that the finding could be in either direction.
A two-tailed test is more likely to produce a significant result.
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Question 222 pts
Why is a one-tailed test considered a more lenient test than a two-tailed test on a sample of data?
Group of answer choices
The alpha is multiplied by two in order to figure the size of the significance area in each tail for a two-tailed test, resulting in more alpha in a two-tailed test.
The tail areas in a two-tailed test are combined in one tail in a one-tailed test, making the critical value less extreme in a one-tailed test than in a two-tailed test.
The one-tailed test has only one critical value, and the two-tailed test has two critical values that both need to be exceeded.
A one-tailed test only tests one hypothesis, but a two two-tailed test tests two hypotheses.
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Question 232 pts
How does a two-tailed test compared to a one-tailed test when given a sample statistic and a fixed alpha level?
Group of answer choices
The critical value to be compared to the statistic would be less extreme with a two-tailed test.
The critical value to be compared to the statistic would be more extreme with a two-tailed test.
The total significance area in the comparison distribution is larger in a two-tailed test.
The total significance area in the comparison distribution is smaller in a one-tailed test.
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Question 242 pts
The time spent on an exam by a class of 100 students is normally distributed with a mean of 50 minutes and a standard deviation of 8 minutes. Using the percentage approximations for the normal curve, what is the percentage of the population of all exam takers that would spend between 50 to 62 minutes on the exam? (Use of Z table is necessary)
Group of answer choices
41.92%
43.32%
8.08%
6.68%
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Question 252 pts
What is the probability of drawing a score from a normal distribution of scores that can be converted into a Z score between +1 and -2? (Use the Z table)
Group of answer choices
.9544
.6826
.3414
.8185
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Question 262 pts
A graduating class in a local high school were surveyed, and 60% of the students have decided to attend Arizona State University. If I randomly draw a student from the graduating class, what is the probability that the chosen student will be attending ASU?
Group of answer choices
.40
40%
.60
60%
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Question 272 pts
What happens as the overlap between the distribution of population 2 and the inferred distribution of population 1 increases?
Group of answer choices
The effect size is smaller.
The effect size is larger.
The significance level rises.
The significance level falls.
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Question 282 pts
Why would a researcher complete a power analysis before conducting a study?
Group of answer choices
To determine the number of participants required for the study.
To determine whether the study should be conducted or not.
To determine the alpha level for the study.
To determine whether to conduct a one-tailed or a two-tailed test with the data.
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Question 292 pts
The raw effect size of a study be converted to a standardized effect size by _______________________.
Group of answer choices
dividing the difference between the two population means by the population standard deviation.
dividing the difference between the two population means by the square root of N
dividing the difference between the two population means by the standard error of the sampling distribution
dividing the difference between the two population means by the sample size
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Question 302 pts
It is hypothesized that bird owners have fewer doctor's visits compared to the general population. To conduct a one-tailed hypothesis test, the researcher sets the α (significance) level at .05. What should be the critical Z value based on the Z table?
Group of answer choices
1.96
-1.645
+1.96 and -1.96
-1.65 and +1.65
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Question 312 pts
A new type of orange has been developed to be bigger than the typical orange, which average 8 oz in weight. The critical Z value for a hypothesis test is 1.28 and the standard error is 2 oz. What is the minimum weight (in oz) of the sample of new oranges to yield a significant test result?
Group of answer choices
10.56+
13.88+
9+
5.04+
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Question 322 pts
A study was conducted on the effects of praise on children's school grades. If the study has high statistical power, it means that the probability is high for ____________.
Group of answer choices
getting a significant test result when praise actually has the predicted effect on grades
not getting a significant result when praise does not actually have the predicted effect on grades
getting a significant test result even when praise does not necessarily have the predicted effect on grades
not getting a significant test result even when praise actually has the predicted effect on grades
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Question 332 pts
A market researcher wants to know if Toyota vehicles have significantly higher MPGs compared to the national statistics. She sets the α (significance) level at .10 for a one-tailed test. The Z statistic calculated from the Toyota sample is 1.62. What is the conclusion from this hypothesis test?
Group of answer choices
The null hypothesis is rejected and Toyota vehicles have significantly higher MPGs compared to the national data.
The null hypothesis is rejected and Toyota vehicles do not have significantly higher MPGs compared to the national data.
The null hypothesis is not rejected and Toyota vehicles have significantly higher MPGs compared to the national data.
The null hypothesis is not rejected and Toyota vehicles do not have significantly higher MPGs compared to the national data.
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Question 342 pts
What is a a sampling distribution?
Group of answer choices
It is a distribution of the means of all possible samples (of a particular size) drawn from a population.
It has a mean and standard deviation which are are smaller than those of the original population from which it is derived.
It has a larger variability compared to the original population from which it is derived.
It is composed of Z scores converted from the original scores in the population.
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Question 352 pts
Compared to a sampling distribution with a mean of 100 and a standard error of 20, what is the Z statistic for the sample that consists of 98, 102, 108, 112.
Group of answer choices
.25
2.5
-.25
-2.5
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Question 362 pts
A teacher conducted a study to see if the students in his school performed significantly worse than the national average on a standardized math test. He calculated the Z statistic to be -1.78 while the critical value for the hypothesis test was -1.645. He would conclude that ___.
Group of answer choices
the null hypothesis was rejected and the students in his school performed significantly worse than the national average.
the null hypothesis was rejected and the students in his school did not perform significantly worse than the national average.
the null hypothesis could not be rejected and the students in his school pefromed significantly worse than the national average.
the null hypothesis could not be rejected and the students in his school did not perform significantly worse than the national average.
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Question 372 pts
The average weight of 49 young males is 170 lbs. This sample is compared to the general population of males in the same age range. The general population mean is 173 lbs and the standard deviation is 5 lbs. What is the standardized effect size of this test?
Group of answer choices
-0.60
.5
.3
3
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Question 382 pts
In a study on work hours, a sample of ASU psychology online students are compared to the general population of ASU online students and the Z statistic for the sample is -1.68. With a one-tailed test with an alpha level of .05, what is the conclusion of the hypothesis test?
Group of answer choices
Fail to reject the null hypothesis.
Reject the null hypothesis.
Reject the alternative hypothesis.
Reject both the null and the alternative hypotheses.
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Question 392 pts
What is the purpose of finding the standardized effect size of a study?
Group of answer choices
To evaluate the practical importance of a result
To double check the test statistic for accuracy
To evaluate the null hypothsis
To see if the hypothesis test is significant or not
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Question 402 pts
What is the term for the standard deviation of the distribution of means (the sampling distribution)?
Group of answer choices
standard error
standard deviation
standard variance
shared variance
In: Statistics and Probability
Listed below are student evaluation ratings of courses, where a rating of 5 is for "excellent." The ratings were obtained at one university in a state. Construct a confidence interval using a 95% confidence level. What does the confidence interval tell about the population of all college students in the state? 4.0, 3.0, 4.0, 4.8, 3.1, 4.5, 3.3, 4.9, 4.5, 4.4, 4.3, 3.8, 3.4, 4.0, 3.9
In: Statistics and Probability
Question 1)
Let's conduct the ANOVA analysis for Charlie's study.
Charlie is testing the mean cuteness scores of a sample of dogs by groups. The groups are pugs, other small dogs, medium dogs, and large dogs (4 groups). There are 5 ratings (cuteness scores) per breed.
The cuteness scores are:
Pugs (5 observations): 8, 9, 9, 7, 8
Other Small dogs (5 observations): 5, 4, 6, 4, 2
Medium (5 observations): 5, 6, 4, 6, 5
Large (5 observations): 6, 5, 9, 3, 4
In the next few items you will be asked to make calculations to conduct the ANOVA analysis with this data.
Part A)
The first step of conducting our analysis will be to calculate the Overall mean and the Group means. Fill in the blanks below:
Round your responses to 1 decimal place.
OVERALL MEAN | |
GROUP MEANS: | |
Pugs | |
Other small dogs | |
Medium | |
Large |
Using Charlie's data, and the means you calculated in the previous question, fill out the ANOVA table with the appropriate degrees of freedom, sum of squares, mean squares, and F-ratio.
You can use excel or R as a calculator, but you MUST calculate them by hand/manually. If you do not provide your work/code for the manual calculations in the previous "question" you will not get full credit.
Degrees of freedom should be provided as integers.
Other values should be rounded to one decimal place.
DF | SS | MS | F | |
Group | ||||
Residual |
Now, calculate the r-squared for the ANOVA analysis you just conducted above.
Express your answer as a proportion. Round your answer to TWO decimal places.
In: Statistics and Probability