What effect will have on the standard error of the mean

Assignment Help Basic Statistics
Reference no: EM13847927 , Length:

Question 1:

A national survey found that 17% Of Australians consume milk with their breakfast. However, in Victoria, a large milk producer believes that more than 17% of Victorians consume milk with their breakfast. To test this idea, a marketing organisation randomly selected 550 Victorians and asked if they consume milk with their breakfast. It was found that 115 did. Using a 0.05 level of significance, test the idea that more than 17% of Victorians consume milk with their breakfast.

Question 2:

A rental car company promotes cheap, affordable, old cars to backpackers. The company is interested in estimating the average number of days its cars have been rented for over past few years. The company has the records for all its cars, but to use this data would be very expensive. To make a quick estimate, a random sample of 32 hire cars is selected from the company records. The number of days each car was hired is given below (in days).

2

3

7

5

8

2

1

5

9

6

3

2

5

10

1

2

4

8

4

3

7

5

8

2

5

3

7

4

9

11

4

3

Using these data, construct a 95% confidence interval to estimate the average number of days a car is rented out. Assume that the number of days a car is rented is normally distributed in the population. What can you conclude from your calculations?

Question 3:

Using a people-counting device at the entry to a particular department store in Sydney, the average number of shoppers visiting the store during any one-hour period was determined as 448 shoppers with a standard deviation of 21 shoppers.

(a) What is the probability that a random sample of 49 different one-hour shopping periods will yield a sample mean between 441 and 446 shoppers?

(b) Interpret your answer in words.

(c) If the random sample size increased to 196 what effect will this have on the standard error of the mean?

Question 4:

The Bureau of Labor Statistics provides compensation information on and services for various positions. As of May 2008, the national average salary for an RN (registered nurse) was $65,130. Suppose the standard deviation is $9385. For a random sample of 100 such nurses find the following:

(a) The probability that the mean of the sample is less than $62,500.

(b) The probability that the sample mean is between $64,000 and $67,500

(c) The probability that the sample mean is greater than $66,000

(d) Explain why the assumption of normality about the distribution of wages was not involved in the solutions parts to a, b, and c.

Question 5:

Sara is a stockbroker and psychic. She claims that she provides clients with stock market advice which is in good harmony with a client's "aura" and "karma" and which is attuned to the client's own personal astrological chart. Daniela is a bit wary of these claims, but decides to invest with Sara for a trial period of one year. She purchases five stocks, on Sara's advice. At the end of the year Daniela checks to see whether she could on an average depend on Sarah's psychic abilities for investment decisions.

(a) State the null and alternative hypotheses, in words and in symbols.

(b) The five stocks that Sara recommended to Daniela had returns of +10%, -15%, +5%, +30%, and -5% over the one-year trial period. (The overall stock market, as measured by the S&P 500, lost 6% over the course of that year.) Compute the test statistic. Explain the choice of your test statistic. Use α = 0.05. Give the p-value.

(c) Based on your calculations do you think Sara has investing abilities based on her being a psychic?

(d) What would be a Type I error in this scenario?

Reference no: EM13847927

Questions Cloud

Effective ehr in your chosen article : Describe five success factors in implementing an effective HER in your chosen article - For each of the five success factors you identified, explain how success was achieved.
Advantages of data pump : Kuhn (2013) suggests that one of the advantages of data pump is that it can be used to populate materialized views using prebuilt tables loaded using data pump. This can be useful for loading large data sets in data warehouse environments
Create a directory called registration : All the pages you created in Assignment One should also be present in Assignment Two not just the new pages or modified pages.
Wlan security project report for bce : A local IT company ZeTech needs your help with a WLAN security project report for BCE. BCE is a medium size sports company and has 8 offices all around the world with 400-450 employees and around 500 daily customers on average
What effect will have on the standard error of the mean : What is the probability that a random sample of 49 different one-hour shopping periods will yield a sample mean between 441 and 446 shoppers and what effect will this have on the standard error of the mean?
Start saving for retirement : Your job pays you only once a year for all the work you did over the previous 12 months. Today, December 31, you just received your salary of $52,000 and you plan to spend all of it. However, you want to start saving for retirement beginning next yea..
What is a troubleshooting model : What is a troubleshooting model? Describe how you would use a troubleshooting model to resolve a user's inability to connect to the Internet from a physically connected networked laptop in an office
What is the monthly deposit : TV’s R Yours is advertising a deal, in which you buy a flat screen TV for $4,769 (including tax) with one year before you need to pay (no interest is incurred if you pay by the end of the one year). How much would you need to deposit at the end of ea..
Determine the irr of each investment : Investment A has the following cash flows: 200,200,300,200 200 Investment B has the following cash flows: 300,300,300,300,300 Both investments have a cost of 350 initially. Indicate which registers, financial or cash flow, can be used to determine th..

Reviews

Write a Review

Basic Statistics Questions & Answers

  At the 001 level of significance test the claim that the

a random telephone survey asked 208 drivers if they run red lights. of the 48 drivers who were 35 years old or younger

  A statistical survey and analyze processed data

Results of a statistical survey and analyze processed data and what proportion of homes subscribe to telephone service from Ashland? Would you say this portion is small, medium, or large?

  Estimate the true mean tensile strength of bars

Estimate the true mean tensile strength of bars of this size and tyoe using 90% confidence interval. List any assumptions you need to make. Given n=150, x(bar)=477N/mm^2, and s=13.

  Home mortgage interest rates

Home mortgage interest rates for 30-year fixed rate loans vary throughout the country. During the summer 2000, data available from various parts of the country suggested that the standard deviation of the interest rates

  Conduct a hypothesis test for each sample

Conduct a hypothesis test for each sample at the 0.01 level of significance and determine what action, if any should be taken.

  Anova-treatments

The data in the next table resulted from an experiment that used a completely random design. Test the null hypothesis that u1 = u2 = u3, where ui represents the true mean for treament i, against the alternative that at least two of the means differ..

  Question a survey shows that 74 of the indians like apples

question a survey shows that 74 of the indians like apples where 68 like orange. what percentage of the indians like

  A random sample of 120 financial analyst was polled on the

a random sample of 120 financial analyst was polled on the issue of company valuation. ninety-six favored inclusion of

  What percentile is associated with a t score of 39 how do

what percentile is associated with a t score of 39? how do you work it

  Consider x1 and x2 given in exercise 3-173 where if x1 and

consider x1 and x2 given in exercise 3-173 where if x1 and x2 are independent random variables with ex12ex25 vx12 vx210

  A group of 2000 randomly selected adults were asked if

question a group of 2000 randomly selected adults were asked if they are in favor of or against cloning. the

  A box contains 2 red and 3 white and 5 green balls two

a box contains 2 red and 3 white and 5 green balls. two balls are drawn out of the box in succession without

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