A ecologist wishes to estimate the mean lifespan for a specific species of bird. Assume that bird lifespan is normally distributed and that each bird's lifespan is independent of all others. The researcher analyzes a random sample of n=7 deceased birds to find out how long they lived for. It is found that the mean lifespan in the sample is y= 5 4 years with standard deviation s=13 years. Choose the correct formula for a 95% confidence interval for the true mean lifespan. X± to.975,n O xt to.975,n-1 n-1 O none of these X+ Z0.975 O x+ to.975,n-1' O xt to.975,n-15

Q: The lengths of pregnancies in a small rural village are Normally distributed with a mean of 270 days…

A:

Q: An Army official wants to estimate the mean weight of a particular type of weapon.  He takes a…

A: Given that, Mean = 48.1 Standard deviation = 0.12 Sample size = 100 98% confidence level

Q: The U.S. Center for Disease Control reports that the mean life expectancy was 47.6 years for whites…

A: From the provided information,

Q: if a sample n = 16, mean = 10.3,standard deviation is 2.6. calculate a 95% confidence interval.

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Q: The heights of 8 Japanese men were taken with sample mean of 155 cm (centimeters) and standard…

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Q: A recent survey of 9 social networking sites has a mean of 12.67 million visitors for a specific…

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Q: Pete kept records of the fuel efficiency of his car. After the first 100 times he filled up the…

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Q: If the variance of a national accounting examination is 828, how large a sample is needed to…

A: Given data: Variance  = 828 Margin of error = 4 points Confidence level = 99 % To calculate the…

Q: Find a 90% confidence interval for the mean of a normal distribution if population variance is 4 and…

A: Given CL = 0.90 Population variance, σ2=4 Sample size, n=8 9,14,10,12,7,13,11,12

Q: The life of sunshine CD players is normally distributed with mean of 4.9 years and a standard…

A: The Z-score of a random variable X is defined as follows: Z = (X – µ)/σ. Here, µ and σ are the mean…

Q: The mean number of English courses taken in a two-year time period by male and female college…

A: Here we will conduct a 2 independent sample t-test to test the equality of the average number of…

Q: The president of a large university wishes to estimate the average age of the students presently…

A: Given that, Mean = 24.2 Standard deviation = 3 Sample size = 40 90% confidence level

Q: The battery of cellphones tend to work less efficiently the longer you have your phone and…

A: We have given that the cellphone battery life follows a normal distribution with a mean of 3 years…

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Q: In 2002, the mean age of an inmate on death row was 40.7 years with a standard deviation of 9.6…

A: Solution

Q: A study of 64 bolts of carpet showed that their average length was 75 yards. The standard deviation…

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Q: Dr. Moore wanted to estimate the mean cholesterol level for all adult men living in Hartford... He…

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Q: A recent study of 28 city residents showed that the mean of the number of years they lived at their…

A: The formula of confidence interval for the population mean is given by                  confidence…

Q: A survey of 30 adults found that the mean age of a person’s primary vehicle is 5.6 years. Assuming…

A: A confidence interval is a type of estimate computed from the statistics of the observed data. This…

Q: A bank loan officer rates applicants for credit. The ratings can be described by a normal model with…

A: Given: μ = ​200 σ = 50

Q: 95% confidence interval of the population mean

A: Given : Sample Size, n = 40 Sample Mean, x̄ = 500 sample standard…

Q: A random sample of 5 months in an urban area showed an average of 28 mail carriers were bitten by…

A: Here we need to construct a 95% confidence interval for the mean number of mail carriers who were…

Q: he average height of students at a school from an SRS of 12 students gave a standard deviation of…

A: Given: Sample size, n=12 Standard deviation, s=2.5 We need to construct a 95% confidence interval…

Q: Find the 90% confidence interval for the standard deviation of the lengths of pipes if a sample of…

A: given data s = 10.2 n = 22 90% CI for σ = ? α = 1 - 0.90 = 0.10df = n - 1 = 21χ2L = χ21-α2,n-1…

Q: Suppose the scores of students on an exam are normally distributed with a mean of 558 and a standard…

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Q: The results of a common standardized test used in physchology research is designed so that the…

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Q: 1900 in a certain county. Of the 124 whites, the mean life span was 45.3 years with a standard…

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Q: The mean reading speed of a random sample of 81 adults is 320 words per minute. Find a 90%…

A: Given: n=81, x=320 and σ=45.   The value of z at 90% confidence level is 1.645. (From the z-table)

Q: Find the 90% confidence interval for the variance and standard deviation of the ages of students at…

A: Confidence interval: The (1-α) % confidence interval for population standard deviation is given by:

Q: Consumer agencies claim that the mean lifespan of a dishwasher is 9.5 years. Your company…

A:

Q: Humerus bones from the same species of animal have approximately the same length-to-width ratios. It…

A: Formula : Standard error = s/√n

Q: A sociologist found that in a sample of 45 retired men, the average number of jobs they had during…

A: Given : population mean ,u = 7.2  population standard deviation,σ = 2.3

Estimation

A new framework of data analysis where the new statistical methods are used for interpreting the results and analyzing the data is known as estimation in statistics.