According to the 2017-2018 U.S. Pet Ownership & Demographics Sourcebook, 38.4% of US households own a dog. Ms Ferguson believes the percent of households who own a dog has changed since 2018, so she polls 90 students and finds that 39 students own a dog. Test Ms. Ferguson’s claim at the α = 0.05 significance level. Regardless of which method you use, sketch a graph showing the critical region and where the test statistic falls - inside or outside the critical region.
In: Statistics and Probability
The average GRE score at the University of Pennsylvania for the incoming class of 2016-2017 was 311. Assume that the standard deviation was 13.4. If you select a random sample of 40 students, what is the probability that the sample mean will be less than 313? Round your answer to three decimal places.
The average GRE score at the University of Pennsylvania for the incoming class of 2016-2017 was 311. Assume that the standard deviation was 13.4. If you select a random sample of 40 students, what is the standard error of the mean? Round your answer to three decimal places.
In: Statistics and Probability
A college admissions officer for the school’s online undergraduate program wants to estimate the mean age of its graduating students. The administrator took a random sample of 40 from which the mean was 24 years and the standard deviation was 1.7 years.
If the mean age of online undergraduate students was 23 years of age, what is the probability that the sample of 40 would have produced a mean age of 24 or higher? Be sure to set up the two competing hypotheses and provide a statistical conclusion statement at a 5% level of significance for your results.
In: Statistics and Probability
Forty randomly selected students were asked the number of pairs of sneakers they owned. Let X = the number of pairs of sneakers owned. The results are as follows.
| X | Frequency |
|---|---|
| 1 | 3 |
| 2 | 3 |
| 3 | 7 |
| 4 | 13 |
| 5 | 13 |
| 6 | 1 |
Find: Sample Mean, Standard Deviation, Relative Frequency and Cumulative Relative Frequency, First and Third Quartiles, What percent of the students owned at least five pairs? (Round your answer to one decimal place.), 40th Percentile and 90th Percentile.
In: Statistics and Probability
72% of all students at a college still need to take another math
class. If 36 students are randomly selected, find the following
probabalities. Round your answers to 4 decimal
places.
a. Exactly 26 of them need to take another math class.
b. At most 25 of them need to take another math class.
c. At least 24 of them need to take another math class.
d. Between 25 and 32 (including 25 and 32) of them need to take
another math class.
In: Statistics and Probability
You are interested in whether a student’s popularity rank is related to his or her leadership rank. You have collected the data, and now you are ready to run the analysis.
Assuming that you end up with a high but negative gamma, what would that mean about the relationship between popularity rank and leadership rank?
Students who rank higher in popularity tend to rank higher in leadership.
There is no relationship between rank in popularity and rank in leadership.
Students who rank higher in popularity tend to rank lower in leadership.
In: Statistics and Probability
A nonprofit company concerned with the school dropout rates has designed a tutoring program aimed at students between 16 to 18 years old. A national center for educational statistics reported that the high school dropout rate for the year 2000 was 10.9%. One school district, who adopted the use of the nonprofit's tutoring program and whose dropout rate has always been very close to the national average, reported in 2004 that 183 of their 1772 students dropped out. Is their experience evidence that the tutoring program has been effective?
In: Statistics and Probability
17.35 Hand Size. A clever way to determine hand size in three dimensions is to measure the volume in ml of water displaced when the hand is dipped in a water container. A study used this method to gather hand volumes of 12 male college students. Here are the measurements:
400, 360, 420, 520, 460, 350, 500, 420, 450, 430, 395, 400
We consider this an SRS of all male college students. Obtain a 95% confidence interval for the mean hand size and interpret it in context.
In: Statistics and Probability
210 students were asked to randomly pick one of the numbers 1,
2, 3, 4, 5, 6, 7, 8, 9, 10. The number 7 was picked by 61
students.
(c) Calculate a 90% confidence interval for the population
proportion. (Round the answer to three decimal places.)
___________to ___________
(d) Calculate a 95% confidence interval for the population
proportion. (Round the answer to three decimal places.)
to
__________to____________
(e) Calculate a 98% confidence interval for the population
proportion. (Round the answer to three decimal places.)
____________to_________
In: Statistics and Probability
The Quinnipiac polling institute claims that 70% of college stu- dents live on campus. A researcher takes a sample of 200 college students to see if the proportion is less. In the researcher’s sample, 132 college students live on campus.
(a) Develop the null and alternative hypotheses.
(b) At α = 0.02, what is the rejection rule?
(c) What is the value of the test statistic z?
(d) Should the researcher reject H0?
(e) Based on your answer in part (d), what is our conclusion for THIS SITUATION? Be specific.
Please write out.
In: Statistics and Probability