Suppose a study is being planned to estimate the relative frequency of companies that are labeled as risky. What sample size is needed so that the standard error will be no larger than 0.016 ?
here as we know that maximum standard error is at p=0.5
therefore required sample size =p(1-p)/(standard error)2 =0.5*(1-0.5)/(0.016)^2 =976.56 ~ 977
Suppose a study is being planned to estimate the relative frequency of companies that are labeled...
C-E needs JMP
Suppose a study is being planned that will investigate whether female Beagles with severe periodontitis (gum and mouth disease) give birth to smaller litters of puppies, on average, than Beagles without periodontitis. Based on previous research, the standard deviation of litter size is estimated to be 2.3 puppies Suppose we suspect that Beagles with periodontitis will give birth to on average 6 puppies whereas Beagles without periodontitis will give birth to on average 5 puppies. a. Using...
Suppose a study is being planned that w investigate whether female Beagles with severe periodontitis (gum and mouth disease) give birth to smaller litters of puppies, on average, than Beagles without periodontitis. Based on previous research, the standard deviation of litter size is estimated to be 2.4 puppies. Suppose we suspect that Beagles with periodontitis will give birth to on average 6 puppies whereas Beagles without periodontitis will give birth to on average 5 puppies a. Using the assumed values...
A study is being planned to estimate the mean number of semester hours taken by students at a college. The population standard deviation is assumed to be σ = 4.7 hours. How many students should be included in the sample to be 99% confident that the sample mean 3 is within one semester hour of the population mean gu for all students at this college?
3. Serum cholesterol levels above 200 mg/dl are considered high. A study is being planned to determine if the mean cholesterol level for adult Canadians exceeds 200. If a t-test is to be used with α= 0.05, what sample size is required to detect a mean cholesterol level as high as 218 with power .95? An earlier study estimated the standard deviation of cholesterol levels among Canadian adults to be about 58.2
Researchers are planning a study to estimate the impact on crop yield when no-till is used in combination with residue retention and crop rotation. Based on data from a meta-analysis of 610 small farms, the researchers estimate there is a 2.5% decline in crop yield when no-till is used with residue retention and crop rotation. Suppose the researchers want to produce a 95% confidence interval with a margin of error of no more than 3.5%. Determine the minimum sample size...
A stratified simple random sample (STSI) is being planned. Information is available from a pilot study on the variance and cost of data collection in stratum h. The size of stratum h is known to be . The cost equation is . The total sample size is . Derive the optimal allocation of units () to the strata.
3 Suppose that a population is being studied that has a known standard deviation of 110. Further suppose a sample of size 90 is taken, resulting in a sample mean of 550. Determine the Point Estimate and the Margin of Error for a 95% Confidence Interval for this sample. Round all calculations to two (2) decimal places. 6 Blank # 1 550 A/ Blank # 2 Question 2 (4 points) Saved Suppose that a population is being studied that has...
A survey is planned to determine what proportion of high-school students in a metropolitan school system have regularly smoked marijuana. The school administrators would like to estimate the proportion with 98 % confidence and a margin of error of no more than 3.25%. It was reported that 26.19% of high school students in a similar metropolitan area regularly smoke marijuana. If this estimate is used, what sample size would be required? n = If the administrators choose not to use...
QUESTION 21 If we change a 90% confidence interval estimate to a 99% confidence interval estimate while holding sample size constant, we can expect a. the width of the confidence interval to increase. b. the width of the confidence interval to decrease. c. the width of the confidence interval to remain the same. d. the sample size to increase. QUESTION 22 Which one of the following is a correct statement about the probability distribution of a t random variable? a....
Suppose that you are wanting to estimate the mean of a
population in which the standard deviation,
, is known to be 5. You take a random sample of size n=50 from the
population and determine that the mean of the sample is 22.4.
a. What is the standard error (of the mean) to two decimal
places?
b. If you wanted 94% confidence in your results, then what would
be the maximum allowable error (error of the estimate), E, to...