Essay on Statistics and Sample Size

Submitted By bj7067

Words: 402

Pages: 2

Open Document

Problems

1. Test the claim that the population proportion of rainy days is less than .13 at the 1% significance level. A sample of 60 days found 7 of them rainy.
2. Find the sample size needed for a confidence interval for the population proportion; margin of error = .005, confidence level = .98.
3. Create a 90% confidence interval for population mean; sample mean = 2.21, population standard deviation = 0.72, sample size = 32.
4. Test the claim that the population mean is not 65 at the 5% significance level. A sample of 114 had a mean of 68 and standard deviation 13.
5. Find the sample size needed for a confidence interval for the population mean; margin of error = 2.2, population standard deviation = 21, confidence level = 90%
6. Create a 95% confidence interval for population mean; sample mean = 10.1, sample standard deviation = 4.2, sample size = 10.
7. Create a 98% confidence interval for population proportion of deaths caused by hanging; number of deaths sampled = 267, number of deaths by hanging = 14.
8. Find the sample size needed for a confidence interval for the population proportion; margin of error = .01, sample proportion = .43, confidence level = 99%.
9. Test the claim that the population mean is at least 91.8 at the 1% significance level. A sample of 16 had a mean of 89.5 and standard deviation 6.2.
10. Find the margin of error of the population mean confidence interval; sample mean = 1.44, sample standard deviation = 0.37, sample size = 47, confidence level = 95%.
11. Test the claim that the average number of videos is more than

Statistics: Larger Sample Size Essay

19 b) Chapter 8 3. a) n=60 standard deviation=15 mean=80 CI=.95 1-.95=.05/2=.025 80+1.96(15/√60)=83.8 80-1.96(15/√60)=76.2 b) 1-.95=.05/2=.025 80+1.96(15/√120)=82.68 80-1.96(15/√120)=77.32 c) The effect of a larger sample size on an interval estimate caused the minimum population to go up and the max population went down.…

Words 488 - Pages 2

Statistical Inference and Interval Estimate Essay

is estimated to lie. In Chapter 6, you were assigned to find interval estimates for a population mean and a population proportion. b) Is finding an interval estimate an example of inferential or descriptive statistics? Explain. It is an interval estimate is an example of…

Words 1232 - Pages 5

Final Exam Cheat Sheet Essay examples

standard to avoid selection bias is to use randomization (ex: bad sampling: voluntary response -‐-‐-‐ good sampling: SRS; stratified random sample; multi-‐stage) N : size of population X − µ σ Corr(X,Y ) = Cov(X,Y ) σ Xσ Y If Corr(X,Y ) = 0, they are uncorrelated. • Independent random variables are always uncorrelated, but the converse is not true - two variables can have…

Words 1721 - Pages 7

Summary 7 Essay

7 To know population mean reflect on the sample mean, we need to know the sample distribution of the sample mean. Sampling distribution：all possible values that can be assumed by that statistic, computed from samples of the same size drawn from the same population In any particular sample the sample mean (or sample variance) will (almost certainly) not equal to population meanμ (or variance 2) Sampling error: The difference between a sample statistic & the population parameter This error is not…

Words 413 - Pages 2

Comp 5 Monte Carlo And Scripts Essay

go and – if you instruct gretl to do so – the outputs will be saved. While it may look complicated, this class will not require any programming skills. Once you understand what a given script does, you will (at most) have to change some values (sample size, parameters) and next save and re-run the script. And then analyze the results using the same tools we used before. Download: mcmc.inp, bivariateGaussian.inp, NewboldDavies.inp, HAC.inp, adf.inp, KPSS.inp, ScalingFactor.inp, apple.csv and PensionScheme…

Words 1618 - Pages 7

Essay on MATH 159

are equal Bartlett's Hypothesis Test(12) 1. Each sample (column) of data is~ Normally Distributed 2. Populations have ~ equal variances Bartlett’s Test (Bartlett’s Hypothesis Test for comparing multiple variances) As long as the smallest variance is not more than 9 time smaller than the largest variance, OK 3. Sample (columns) are simple random samples 4. Sample (columns) are independent 5. Sample (columns) are have~=samples sizes (n) Binomial Distribution二项分布（5） A specific type…

Words 1611 - Pages 7

Essay on wk 5 DQ Team A

statistical tests that are appropriate for different and certain situations. Some of these statistical tests are the z and t tests, Chi-squared, and ANOVA tests. The t test is most appropriate when you have a sample size less than 30 while the z test is most appropriate when a sample size is larger than 30. In order to use the z test you must know your standard deviation whereas the t test does not require it. The formula for the z test is as follows: z = (X-u)/s and the formula for the t test…

Words 509 - Pages 3

Measurement Plays A Major Role In Scientific Method

number that are known to be correct. Also expressed using scientific notation. Sample: Subset of a population (“N”), usually a small proportion of the individuals. Sampling units must represent the range and frequency of values in the population. Sample size (“n”) is always reported Sample size can’t be increased by repeating measurements on the same sampling unit. More units measured increase sample size. Part B: Organizing Data Data is grouped according to qualitative or quantitative…

Words 831 - Pages 4

Exam 3 Study guide Essay

Why do we draw samples in marketing? What is a sampling frame? a list of the items or people forming a population from which a sample is taken. What are the steps in drawing a sample? 1. Define population Bases for Defining Population Geography Demographics Usage Rate Awareness 2. Choose data collection method 3. Choose a sampling frame 4. Select sampling method 5. Determine sample size 6. Develop plan for selecting sampling elements 7. Execute plan Know what is involved in the validation…

Words 391 - Pages 2

M & M Project

M&M PROJECT Statistics 300 23June2013 First to get started with the project three 1.69 ounce bags of plain M&M’s were purchased from Shoppers, and 2 7-11’s. These bags will help with taking a sample of the population that is produced. Purchasing the bags from three different stores will help with the results of the project being meaningful because it is assured that the samples will be truly random. Random sampling is when all members of a group have an equal and independent…

Words 944 - Pages 4