Identify the null hypothesis and the alternative hypothesis

Assignment Help Basic Statistics
Reference no: EM131002777

1. True or False. Justify for full credit.

(a) The standard deviation of a data set cannot be negative.

(b) If P(A) = 0.4 , P(B) = 0.5, and A and B are disjoint, then P(A AND B) = 0.2.

(c) The mean is always equal to the median for a normal distribution.

(d) A 95% confidence interval is wider than a 98% confidence interval of the same parameter.

(e) In a two-tailed test, the value of the test statistic is 1.5. If we know the test statistic follows a Student's t-distribution with P(T < 1.5) = 0.98, then we fail to reject the null hypothesis at 0.05 level of significance .

2. Identify which of these types of sampling is used: cluster, convenience, simple random, systematic, or stratified. Justify for full credit.

(a) A STAT 200 professor wants to estimate the study hours of his students. He teaches two sections, and plans on randomly selecting 10 students from the first section and 15 students from the second section.

(b) A STAT 200 student is interested in the number of credit cards owned by college students. She surveyed all of her classmates to collect sample data.

(c) The quality control department of a semiconductor manufacturing company tests every 100th product from the assembly line.

(d) On the day of the last presidential election, UMUC News Club organized an exit poll in which specific polling stations were randomly selected and all voters were surveyed as they left those polling stations.

3. There are 1000 students in a high school. Among the 1000 students, 800 students have a laptop, and 300 students have a tablet. 250 students have both devices. Let L be the event that a randomly selected student has a laptop, and T be the event that a randomly selected student has a tablet. Show all work. Just the answer, without supporting work, will receive no credit. (a) Provide a written description of the event L OR T. (b) What is the probability of event L OR T?

4. Consider rolling two fair dice. Let A be the event that the two dice land on different numbers, and B be the event that the first one lands on 6.

(a) What is the probability that the first one lands on 6 given that the two dice land on different numbers? Show all work. Just the answer, without supporting work, will receive no credit.

(b) Are event A and event B independent? Explain.

5. There are 8 books in the "Statistics is Fun" series.

(a) How many different ways can Mimi arrange the 8 books in her book shelf?

(a) Mimi plans on bringing two of the eight books with her in a road trip. How many different ways can the two books be selected

6. Mimi just started her tennis class three weeks ago. On average, she is able to return 20% of her opponent's serves. Assume her opponent serves 10 times.

(a) Let X be the number of returns that Mimi gets. As we know, the distribution of X is a binomial probability distribution. What is the number of trials (n), probability of successes (p) and probability of failures (q), respectively?

(b) Find the probability that that she returns at least 1 of the 10 serves from her opponent. Show all work. Just the answer, without supporting work, will receive no credit.

7. Assume the weights of men are normally distributed with a mean of 172 lb and a standard deviation of 30 lb. Show all work. Just the answer, without supporting work, will receive no credit.

(a) Find the 80th percentile for the distribution of men's weights.

(b) What is the probability that a randomly selected man is greater than 185 lb?

8. Assume the IQ scores of adults are normally distributed with a mean of 100 and a standard deviation of 15. Show all work. Just the answer, without supporting work, will receive no credit.

(a) If a random sample of 25 adults is selected, what is the standard deviation of the sample mean?

(b) What is the probability that 25 randomly selected adults will have a mean IQ score that is between 95 and 105?

9. A survey showed that 80% of the 1600 adult respondents believe in global warming. Construct a 95% confidence interval estimate of the proportion of adults believing in global warming.

10. In a study designed to test the effectiveness of acupuncture for treating migraine, 100 patients were randomly selected and treated with acupuncture. After one-month treatment, the number of migraine attacks for the group had a mean of 2 and standard deviation of 1.5. Construct a 95% confidence interval estimate of the mean number of migraine attacks for people treated with acupuncture.

11. Mimi is interested in testing the claim that more than 75% of the adults believe in global warming. She conducted a survey on a random sample of 100 adults. The survey showed that 80 adults in the sample believe in global warming. Assume Mimi wants to use a 0.05 significance level to test the claim.

(a) Identify the null hypothesis and the alternative hypothesis.

(b) Determine the test statistic. Show all work; writing the correct test statistic, without supporting work, will receive no credit.

(c) Determine the P-value for this test. Show all work; writing the correct P-value, without supporting work, will receive no credit.

(d) Is there sufficient evidence to support the claim that more than 75% of the adults believe in global warming? Explain.

Reference no: EM131002777

Questions Cloud

Article 6 of the treaty on european union : Article 6 of the Treaty on European Union, called the Maastricht Treaty, states the EU is founded on: private markets   stare decisis
What is the difference between an acquisition and a merger : What is the difference between an acquisition and a merger?
A non-governmental organization : You work for a Non-Governmental Organization who are into provision suitable drinking water needs for needy and deprived communities in the Brong Ahafo Region of Ghana.  The Organization has recently sunk forty (40) boreholes in some of the communiti..
Conflict resolution research and to critically review : his Essay assignment requires you to find at least five quality sources which report on a particular aspect or theme of negotiation or conflict resolution research and to critically review their findings. Please check requirement.
Identify the null hypothesis and the alternative hypothesis : Mimi is interested in testing the claim that more than 75% of the adults believe in global warming. She conducted a survey on a random sample of 100 adults. Identify the null hypothesis and the alternative hypothesis. Determine the test statistic...
Prompt method to get the investment amount : Modify the the JavaScript code so it provides for the option buttons. When the user click the Yearly Interst button, the application should compound the interest yearly, when the user clicks the Monthly Interest button, the application should comp..
Sachs brands defined benefit pension plan : Calculate the effect of the change in the assumed discount rate on the PBO at the beginning of 2012 with respect to Davenport.
The student is required to find five sources : The student is required to find five sources related to the topic, with a least two being electronic sources and two paper sources. the student has to briefly describe the content of each source and evaluate it as to its reliability for content and a..
Endorsed a cheque and then subsequently lost : If I endorsed a cheque and then subsequently lost it. Someone (Person A) found the cheque and then negotiated it to another person (Person B) for value but not in good faith, and then the bank paid out the cheque to Person B. Who do I have a claim ag..

Reviews

Write a Review

 

Basic Statistics Questions & Answers

  Using a 001 significance level test the inspectors claim

the acme bacon company distributes bacon in packages labelled 500 grams. an inspector randomly selects 49 of these

  T-tests and calculating right-tail p-value

The Web-based company Oh Baby! Gifts has a goal of processing 95 percent of its orders on the same day they are received. If 485 out of the next 500 orders are processed on the same day

  The cutoff for mathematics scores is 550 how many texas men

groupmeanstdevpopulation nmen51411280382women48510392420the cutoff for mathematics scores is 550. how many texas men

  Problem regarding the variables and distributions

Welcome to this graduate course in statistics. No matter what your experiences and feelings about statistics are at this time, you will likely find many practical connections to life as you work through this course.

  Modelling using the poisson probability distribution

The number of hurricanes that are formed during each hurricane season can be modeled using the Poisson probability distribution.

  What is the chance that sample families will not own cars

As part of an opinion survey, a simple random sample of 1,500 families is chosen. What is the chance that between 9% and 11% of the sample families will not own cars?

  Determine the standard error of sample mean

mean is calculated for each sample, then the average distance between M and u would be:

  Identify the kind of random variable

Classifcation Which of the following are continuous variables and which are discrete?

  What would average be for all sample means from samples

The average age for employees at an amusement park is 24 years old with a standard deviation of 2.5 years. Suppose random samples of 40 employees are selected. What would the distribution of average ages from samples of this size look like? Why?

  Compute an adjusted exponentially smoothed forecast

Compute an exponentially smoothing forecast using an alpha value of .30. Compute an adjusted exponentially smoothed forecast (alpha = .30 and beta= .20).

  Athletic persons and second non-athletic ones

The only difference is that the first group is comprised of athletic persons and the second of non-athletic ones.

  Find probability that a was actually telling the truth

Suppose that A makes a statement, and then D says that C says that B says that A was telling the truth. What is the probability that A was actually telling the truth?

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd