You are a researcher studying the lifespan of a certain species of bacteria.  A preliminary sample of 25 bacteria reveals a sample mean of ¯x=72x¯=72 hours with a standard deviation of s=5.8s=5.8  hours.  You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.6 hours at a 98% level of confidence. What sample size should you gather to achieve a 0.6 hour margin of error? Round your answer up to the nearest whole number.

Q: It takes an average of 13.1 minutes for blood to begin clotting after an injury. An EMT wants to see…

A: The population mean or the hypothesized mean is .The sample size is .The sample mean is .The sample…

Q: The mean wingspan of a sample of 31 birds of a particular species is 30 inches.  The standard…

A: Sample size n =31 Sample mean=30 Population standard deviation =4

Q: support the scientist’s estimate

A: A scientist estimates that the mean nitrogen dioxide level in Westman is greater than 28 parts per…

Q: You are a researcher studying the lifespan of a certain species of bacteria.  A preliminary sample…

A: The provided information are: Population standard deviation σ=4 Margin of error (E) = 0.5 Confidence…

Q: (b) Find the 1oth percentile of x. Round the answer to at least two decimal places. The 10t…

A: Given that.   X~N( μ , ?^2 )   μ= 31    , ?=6  ,n=60   Z-score =( x - μ )/?

Q: The average income of 15 families who reside in a large metropolitan East Coast city is $62,456. The…

A: Given that    Sample sizes n1=14   , n2=11        Sample means X̄1=62456     , X̄2= 60213    s1…

Q: The scores on a mathematics exam have a mean of 71and a standard deviation of 8. Find the x-value…

A: Let X denote the scores on a mathematics exam and it follows normal distribution with mean of…

Q: researcher in a large university claimed that the mean health care expenses differ from the national…

A: From the given information, Consider,  μ=$1570n=50x=$1680s=$180α=0.05

Q: The concentration of benzene was measured in units of milligrams per liter for a simple random…

A: Let,  μ1 :  the population mean benzene concentration for untreated water and  μ2: the population…

Q: You are conducting an experiment to examine the anxiety levels of a group of Engineering studer The…

A:

Q: deviation of s=7s=7  hours.  You would like to estimate the mean lifespan for this species of…

A:

Q: An experiment was conducted to estimate the effect of smoking on the blood pressure of a group of 31…

A: The sample size is 31, sample mean is 9.1 and sample standard deviation is 5.3.

Q: duction of 12 male red-winged blackbirds before and after receiving testosterone implants was…

A: given:  d = 0.056  sd = 0.175  probability of 0.8, mean change of 0.01

Q: A sample of 14 television tubes produced by a company showed a mean lifetime of 1838 hours and a…

A: Given that, n=14σ=233x¯=1838 The formula for calculating the standard deviation of the population of…

Q: In a population of exam scores, a score of X = 88 corresponds to z = 2 and a score of X = 79…

A: From the provided information, A score of X = 88 corresponds to z = 2 A score of X = 79 corresponds…

Q: A sample of size 60 will be drawn from a population with mean 31 and standard deviation 6 .Find…

A: Given that.   X~N( μ , ?)   μ=31     , ?=6   Z-score =( x - μ )/?

Q: A population with µ = 46 and s = 9 is transformed into z-scores. After the transformation, what is…

A: Answer: For the given data,

Q: A standardized test, deigned to measure the mathematical skill level of seventh graders is said to…

A: Given information: μ=75, n=25x¯=79, s=10 Null hypothesis: H0 : μ=75 Alternative hypothesis: HA :…

Q: A random sample of 46 adult coyotes in a region of northern Minnesota showed the average age to be x…

A:

Q: You are a researcher studying the lifespan of a certain species of bacteria.  A preliminary sample…

A: Given information- Sample standard deviation, s = 6 hours Confidence interval = 0.98 Significance…

Q: In an exam for a statistics class, the class average is 68 with a standard deviation 4. If a student…

A: Given mean μ= 68, standard deviation σ= 4 Let X: score of the students = 75

Q: A cohort of patients have lost on average 23 pounds and the standard deviation of the sample is 1.2…

A: We have been given that a cohort of patients have lost on average 23 pounds and the standard…

Q: You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of…

A: Given that,Sample mean (X bar) = 74, standard deviation (S) =4.2 and sample size, n = 25.And also…

Q: You are a researcher studying the lifespan of a certain species of bacteria.  A preliminary sample…

A:

Q: A researcher wants to know the lifetime of a "BL" brand lamp. For necessity research, it takes 9…

A: Given : Population Mean life , μ = 1500 hrs Population standard deviation , σ = 111 hrs

Q: The scores on a standardized test are normally distributed with a mean of 90 and standard deviation…

A: The test score is 0.6 standard deviations above the mean is obtained below: From the given…

Q: A population has a mean of 75 and a standard deviation of 15 you randomly sample nine people from…

A: Given population have mean 75 and standard deviation 15. A sample of 9 people from the population is…

Q: Unfortunately, arsenic occurs naturally in some ground water. A mean arsenic level of u = 8 parts…

A: One sample z-test: One sample z-test is used to test the significance difference between population…

Q: You run a multiple regression with 64 cases and three explanatory variables. Software output gives…

A:

Q: We have a recent set of data of n=30 Americans, the sample mean = 14 hours per day, the standard…

A: The sample mean and population mean is whether related or not is calculated using the z test when…

Q: For a population with  = 150, a raw score of X = 125 corresponds to z = -2.00.  What is the standard…

A: Consider that the mean and standard deviation of a random variable x are µ and σ, respectively.…

Q: A population has a mean of 250 and a standard deviation of 24. What value from the population has a…

A: Solution

Q: A researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 35…

A: Given : Margin of error =0.5 Standard deviation (s) =7 Confidence level =95%

Q: The mean score of Grade 11 students in a General Math examination was observed to be 75 with a…

A:

Q: In the year 2033, katy perry is a leading traveling nurse. Katy is interested in reducing the mean…

A: Population mean, μ=8.6 Sample size, n=46 Sample mean, x¯=8.1  Sample sd, s=1.2 α=0.05

Q: From generation to generation, the mean age when smokers first start to smoke varies. A survey of 20…

A: Given Information :  From generation to generation, the mean age when smokers first start to smoke…

Q: onsider a population that has a score of X = 15 associated with a z-score of +1.50. What does this…

A: Given: X=15  z-score =+1.50

Q: A population of scores has µ=44. In this population, a score of X= 40 corresponds to z= - 0. 50.…

A:

Q: A homeowner has installed a new energy-efficient furnace. It is estimated that over a year the new…

A: We know that if; X1,X2,...,Xn~Normal(μ,σ2), independently Then; Sn=X1+X2+...+Xn~Normal(nμ,nσ2)

Q: Ann thinks that there is a difference in quality of life between rural and urban living. She…

A: Rural town:Sample size Sample mean Sample standard deviation Urban town:Sample size Sample mean…