Question

In: Math

you decide that you want to examine the lead concentrations in blue crabs in the Chesapeake...

you decide that you want to examine the lead concentrations in blue crabs in the Chesapeake Bay. Before you collect the crabs, you would like to determine how many crabs should be in your sample. You decide on a Type I error rate of 0.05 and want to achieve power of 0.80. Based on previous studies you assume a population standard deviation of 0.10 ug Pb/g crab. You want to be able to detect an effect size of 0.01 ug Pb/g crab (assume a one-sided test). How many crabs should you include in your random sample?

Solutions

Expert Solution

Level of Significance ,    α =    0.05                              
std dev =    σ =    0.100                              
power =    1-ß =    0.8                              
ß=       0.2                              
δ=      0.01                              
                                      
Z ( α ) =       1.6449   [excel function: =normsinv(α)                          
                                     
Z (ß) =        0.8416   [excel function: =normsinv(ß)                         
                                      
sample size needed =    n = ( ( Z(ß)+Z(α) )*σ / δ )² = ( (   0.8416   +   1.6449   ) *   0.1   /   0.01   ) ² =   618.2557
                                      
so, sample size =        619   


Related Solutions

A researcher claims that the stomachs of blue crabs from Location A contain more fish than...
A researcher claims that the stomachs of blue crabs from Location A contain more fish than the stomachs of blue crabs from Location B. The stomach contents of a sample of 14 blue crabs from Location A contain a mean of 199 milligrams of fish and a standard deviation of 36 milligrams. The stomach contents of a sample of 7 blue crabs from Location B contain a mean of 183 milligrams of fish and a standard deviation of 43 milligrams....
Suppose that you are a member of a team assembled to examine needs and decide on...
Suppose that you are a member of a team assembled to examine needs and decide on an IT strategy of non-profit organization. What are the steps you will take in understanding the needs, the costs, alternatives and implementation?
You are a new blue jeans manufacturer and is starting operations this month. You must decide...
You are a new blue jeans manufacturer and is starting operations this month. You must decide on which cost accounting system to use in order to account for your manufacturing costs. You can choose from using the job order cost system or the process cost system. What system would you choose and why? Please be detailed in your answer as to why you chose the specific system.
I want you to examine the change in value of a game released in the summer...
I want you to examine the change in value of a game released in the summer of 2004. It released at a price of $375, and the more recent ones on eBay sold for roughly $2400. For simplicity, you should consider 2004 as time 0 (t = 0) to keep the numbers more manageable. I recommend rounding values to 3 decimal places where applicable. a) Find a linear appreciation (for money, we say “appreciation” rather than growth) model for the...
Please choose any company You are to decide on an organization that you want to evaluate....
Please choose any company You are to decide on an organization that you want to evaluate. It is important that you have some knowledge of the inner workings of the company-- its struggles, its strengths, its culture, and so forth -- or have access to the organization to conduct interviews to collect the needed information. You will produce a written report. The paper should include the following sections: 1. Organization Background - Provide just enough details on the company for...
It is your 25th birthday (end of 25 years) and you decide that you want to...
It is your 25th birthday (end of 25 years) and you decide that you want to retire on your 65th birthday (end of 65 years - 40 years later). Your salary is $55,000 per year and you expect your salary to increase by 3% each year for the next 40 years. When you retire, you want your retirement fund to provide an annual payment equal to 80% of your salary at age 65 and to increase by 2% a year...
Q2. Now that you know the answer to the above question, you decide that you want...
Q2. Now that you know the answer to the above question, you decide that you want to predict the amount of trash that all of them can pick up. You find strong correlations between certain data points and trash collected, and you want to develop a predictive model to see the result. Use the attached data (Trash data) to forma multiple regression model, and explain the usefulness of the model. Use the analysis tool in Excel to calculate the model...
You decide you want your child to be a millionaire. You have a daughter today and...
You decide you want your child to be a millionaire. You have a daughter today and you deposit $59,000 in an investment account that earns 7.5% per year. The money in the account will be distributed to your daughter whenever the total reaches $3,750,000. How old will your daughter be when she gets the money (rounded to the nearest year)? Please show work
You decide that you want to save 767,393 dollars for retirement. Assuming that you are 25...
You decide that you want to save 767,393 dollars for retirement. Assuming that you are 25 years old today, will retire at the age of 65, and can earn a 8 percent annual interest rate on your deposits, how much must you deposit each year to meet your retirement goal? (your first deposit will be one year from now and your last deposit will be 40 years from today, i.e. 40 deposits) Hint : The number of years for FVIFA...
You own and manage a pretzel and lemonade concession cart. You decide that you want to...
You own and manage a pretzel and lemonade concession cart. You decide that you want to sell your products at a NASCAR® race weekend in Loudon, NH. The track charges $1,000 in rent for the entire weekend. Food and beverage costs run about 20% of sales. You have to pay an employee $400 to run the cart over the weekend. You provide incentives of 5% of sales. Your accountant allows you to take $250 in depreciation expenses for this weekend...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT