A biologist wishes to estimate the effect of an antibiotic on the growth of a particular bacterium by examining the mean amount of bacteria present per plate of culture when a fixed amount of the antibiotic is applied. Suppose he estimates that s = 14 cm2 and that he has a sample size of 35 with sample mean equal to 110 cm2. Assume all conditions are met.
(a) What is the the t* value needed to construct a 99% confidence interval for the mean? Be sure to use the table, and round down your df.
(b) Let μ denote the population mean amount of bacteria present per plate of culture. Calculate the 99% confidence interval for μ. ( , ) (Use 2 decimal places.)
A biologist wishes to estimate the effect of an antibiotic on the growth of a particular...
A biologist wishes to estimate the effect of an antibiotic on the growth of a particular bacterium by examining the mean amount of bacteria present per plate of culture when a fixed amount of the antibiotic is applied. Suppose he estimates that s = 10 cm2 and that he has a sample size of 35 with sample mean equal to 110 cm2. (a) What is the standard error of the sample mean? b) What is the the t* value needed...
part a: ***the answer is not*** 2.19 2.728 2.73 2.44 2.14 2.13 part b: ***the answer is not**** (108.005, 119.995) (108, 120) Please help. i will rate A biologist wishes to estimate the effect of an antibiotic on the growth of a particular bacterium by examining the mean amount of bacteria present per plate of culture when a fixed amount of the antibiotic is applied. Suppose he estimates that s 13 cm2 and that he has a sample size of...
by examining the mean amount of bacteria present per plate of culture when a fixed amount of the antiblotic is applied. Previous exper with the antiblotic on this type of bacteria Indicates that the standard deviation of the amount of bacteria present is approximately 19 cm2 Use this to determi e the nur ber of obervations (cultures that must be developed and then tested) to estimate the mean amount of bacteria present, using a 99% confidence interval with a half...
A researcher wishes to study whether an antibiotic will inhibit the growth of bacteria in a culture. The researcher inserts the antibiotic into 40 cultures and finds that 30 have reduced growth. A control group of 40 cultures is not given the antibiotic, and 10 of these have reduced growth. Find the margin of error for a 99% confidence interval of the difference in proportion of antibiotic and non-antibiotic cultures.
A researcher wishes to estimate the percentage of adults who support abolishing the penny. What size sample should be obtained if he wishes the estimate to be within 5 percentage points with 99% confidence if (a) he uses a previous estimate of 26%? (b) he does not use any prior estimates?
A researcher wishes to estimate the percentage of adults who support abolishing the penny. What size sample should be obtained if he wishes the estimate to be within 55 percentage points with 99% confidence if (a) he uses a previous estimate of 38%? (b) he does not use any prior estimates?
A researcher collects a sample of 16 measurements from a population and wishes to find a 90% confidence interval for the population mean. What value should he use for t*? (Recall that the number of degrees of freedom for a one-sample t-test is given by equals df=1, where n is the sample size.) LOADING... Click the icon to view the t-distribution table. To find a 90% confidence interval for the population mean, he should use nothing for t*. (Round to...
A botanist wishes to estimate the typical number of seeds for a certain fruit. She samples 73 specimens and counts the number of seeds in each. Use her sample results (mean = 66.5, standard deviation = 6.3) to find the 99% confidence interval for the number of seeds for the species. Enter your answer as an open-interval (i.e., parentheses) accurate to 3 decimal places. 99% C.I. =
Question 13 D 1 pts A university of dean of students wishes to estimate the average number of hours students spend doing homework per week. The standard deviation from a previous study is 6.2 hours. How large a sample must be selected if he wants to be 99% confident of finding whether the true mean differs from the sample mean by 1.5 hours? 1 pts Question 14 If the variance of a national accounting examination is 900, how large a...
pense QUESTION 1 A long distance phone company wishes to estimate the mean duration of long-distance calls originating in California. A random sample of 15 long-distance calls originating in California yields the following call durations, in minutes 2 5 14 11 22 28 32 21 16 15 1 19 12 2 37 Use the data to obtain a point estimate of the mean call duration for all long-distance calls originating in California 15.3 minutes 13.8 minutes 15,8 minutes 13.9 minutes...