Then the upper limit will be at 3.15 + 1.5 * 0.0878. So we have 9.87 plus or minus 1.96 times 0.27 over the square root of 18 smell will take that into a calculator. (a) Find the sample standard deviation $s_{x}$ for these measurements. The mean concentration was $\bar{x}=5.35 \mathrm{mg} / \mathrm{dl} .$ The distribution of uric acid in healthy adult males can be assumed to be normal, with $\sigma=1.85 \mathrm{mg} / \mathrm{dl}$. (Round up to the nearest whole number.) There is a known standard deviation of 7.0 hours. Attached is the spreadsheet the answer should go into. (4) Find the sample size necessary for an 80% confidence level with a maximal margin of error E = 0.12 for the mean weights of the hummingbirds. Plasma Volume Total plasma volume is important in determining the required plasma component in blood replacement therapy for a person undergoing surgery. And so for here are critical. ), (2) What conditions are necessary for your calculations? Based on previous studies, we can assume that the weights of Allen s hummingbirds have a normal distribution, with ? Start Your Numerade Subscription for 50% Off!Join Today. So for a first we need to identify our value of Alfa. (Round up to the nearest whole number.). (b) What conditions are necessary for your calculations? Over a period of months, an adult male patient has taken eight blood tests for uric acid. Course Hero is not sponsored or endorsed by any college or university. Which distribution should you use for this problem? E. The probability that this interval contains the true average weight of Allen's hummingbirds is 0.20. Calculate the error bound.e. (Use whatever you find.) The average weight for these birds is $\bar{x}=3.15$ grams. The weights of full boxes of a certain kind of cereal are normally distributed with a standard deviation of 0.27 oz. $\sigma=$ _____iii. Create your account. 2 - (a) Find an 80% confidence interval for the. average weights of Allen's hummingbirds in the study region. It's a little bit more narrow on our second confidence interval. Formulas are the same as when a normal distribution is used, the exception being that a t-score is used in the calculation of the confidence interval as opposed to a z-score. Please help! Look up the Z value corresponding to a p value of 0.9 (for the 90% upper cut-off point). (b) Find a $95 \%$ confidence interval for the population mean annual number of reported larceny cases in such communities. Find a $90 \%$ confidence interval for the population mean cash value of this crop. EMAILWhoops, there might be a typo in your email. b) The probability that this interval contains the true average weight of Allen's hummingbirds is 0.20. c) We are 20% confident that the true average weight of Allen's hummingbirds falls within this interval. The average weight for these birds is x = 3.15 grams. © copyright 2003-2020 Study.com. PDF attached, please let me know if I need to include anything else. - Procedure, Interpretation & Examples, Frequency & Relative Frequency Tables: Definition & Examples, Population & Sample Variance: Definition, Formula & Examples, Descriptive & Inferential Statistics: Definition, Differences & Examples, What is a Null Hypothesis? uniform distribution of weights normal, (c) Interpret your results in the context of this problem. Show your work. In complete sentences, give an interpretation of what the interval in part f means. Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther. Sketch the graph.iii. Services, Using the t Distribution to Find Confidence Intervals, Working Scholars® Bringing Tuition-Free College to the Community. So are lower limit is 9.87 minus 2.58 times 0.27 divided by the square root of 18 and we get 9.7 zero six. Sketch the graph.iii. Weights of Elephants A sample of 8 adult elephantshad an average weight of $12,300$ pounds. We are $80 \%$ confident that the true populationd. hummingbirds. Black Friday is Here! I was sick for a few days and I missed lecture....I have no idea how to do this :(. It was revealed that they used them an average of six months with a sample standard deviation of three months. Based on previous studies, we can assume that the weights of Allen's hummingbirds have a normal distribution, with σ = 0.26 gram. (Select, all that apply.) What is the point estimate for $\mu,$ the mean circumference of all oranges in the shipment?c. $\quad \mathrm{s}_{\mathrm{X}}=$ _____b. for the mean of a sample of 15 is 0.34 / sqrt 15 = 0.0878. = 0.33 gram. Sketch the graph.iii. There is a 20% chance that the interval is one of the intervals containing the true average weight of Allen's hummingbirds in this region. (c) Find a $99 \%$ confidence interval for the population mean annual number of reported larceny cases in such communities. Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther (Reference: Hummingbirds by K. Long and W. Alther). So since it's a 95% confidence interval, that means Alfa is 0.5 So are critical value for a is going to be 1.96 if we use our table. = 3.15 grams. I need the following assignments answers. The average weight for these birds is x? Say this value is 1.5. $n=$ _____b. The sampling error given by Yankelovich Parthers, Inc. (which conducted the poll) is $\pm 3 \% .$ In one to three complete sentences, explain what the $\pm 3 \%$ represents. Suppose that a committee is studying whether or not there is waste of time in our judicial system. (b) What conditions are necessary for your calculations? Calculate the error bound.f. All rights reserved. In complete sentences, explain why the confidence interval in part $f$ is larger than the confidence interval in part e.h. Calculate the error bound.e. (d) Sample Size Find the sample size necessary for a $99 \%$ confidence level with maximal margin of error $E=2.50$ for the mean plasma volume in male firefighters. 3.04 to 3.26$E=0.11$b. The assignments and ebook chapters are below. a) We are 80% confident that the true average weight of Allen's hummingbirds falls within this interval. Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther.â Suppose a small group of 11 Allen's hummingbirds has been under study in Arizona. Suppose a small group of 17 Allen's hummingbirds has been under study in Arizona. (a) Find an 80% confidence interval for the average weights of Allen's hummingbirds in the study region. The average weight for these birds is  = 3.15 grams. As the confidence levels increase, do the confidence intervals increase in length? Whoops, there might be a typo in your email. The average weight for these birds is x = 3.15 grams. (c) Interpret your results in the context of this problem. The average weight for these birds is x = 3.15 grams. (Reference: See Problem 16.) Based on previous, studies, we can assume that the weights of Allen's. State the confidence interval.ii. Is 31 too old to start working on a Math degree? (a) Find a $95 \%$ confidence interval for the population mean concentration of uric acid in this patient's blood. What is the margin of error? We're going to find to your 0.58 as our critical value. The sample mean is 100. Which distribution should you use for this problem? Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther (Reference: Hummingbirds by K. Long and W. Alther). lower limit upper limit margin of error. We are interested in the population proportion of adult Americans who feel that crime is the main problem.a. Sketch the graph.iii. Allen s hummingbird (Selasphorus sasin ) has been studied by zoologist Bill Alther A small group of 15 Allen s hummingbirds has been under study in Arizona. The average weight for these birds is x? The population standard deviation is known to be 0.1 ounce.a.i. It is interested in the mean amount of time individuals waste at the courthouse waiting to be called for jury duty. Hint: 1 ton is 2000 pounds. The average weight for these birds is x = 3.15 grams. Based on previous studies, we can assume that the weights of Allen's hummingbirds have a normal distribution, with {eq}\sigma = 0.36 (b) What conditions are necessary for your calculations? (Round your answers to two decimal places. Define the random variables $X$ and $\overline{X}$ in words.c. The average weight for these birds is x= 3.15 grams. (e) the person measuring the children's weights does so without any systematic error. Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther.† Suppose a small group of 15 Allen's hummingbirds has been under study in Arizona. (c) Suppose the $x$ distribution has $\sigma=10 .$ Compute a $90 \%$ confidence interval for $\mu .$ What is the value of the margin of error? Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther.† Suppose a small group of 17 Allen's hummingbirds has been under study in Arizona.