A random sample of 80 recorded deaths in the Philippines during the past year showed an average life span of 72.30 years. Assuming a population standard deviation of 7.20 years, does this seem to indicate that the: mean life span today is greater than 75 years? Use a 95 % confidence interval.

Q: When the standard deviation used to construct a confidence interval for a population mean increases,…

A: Given data: When the standard deviation used to construct a confidence interval for a population…

Q: A survey of 100 retailers revealed that the mean after-tax profit was $80,000. Assuming that the…

A: Given data,n=100σ=15,000x=80,000z-value at 95% confidence is Zc=1.96

Q: How large a sample should be selected to provide a 95% confidence interval with a margin of error of…

A: Population standard deviation, sigma is 60.The z-critical value for 95% confidence interval is…

Q: Use these data and a population standard deviation of 1.11 to construct a 98% confidence interval to…

A: The sample of 36 women's who had babies in the hospital during the past year is taken. The…

Q: How large a sample should be selected to provide a 90% confidence interval with a margin of error of…

A:

Q: How large a sample should be selected to provide a 99% confidence interval with a margin of error of…

A: Given,standard deviation(σ)=50margin of error (E)=10α=1-0.99=0.01α2=0.005Z0.005=2.58

Q: A sample of 23 provided a sample mean of 158 and a sample standard deviation of 20. Find the value…

A: Given that Sample size n = 23 Sample mean = 158 Sample SD = 20

Q: A sample of 49 managers reveals a sample mean of $45,420. The standard deviation of the samp is…

A: As the population standard deviation is not known, we will use t-distribution. The number of degrees…

Q: The mean time it takes for a random sample of 758 airplanes to fly from Florida to New York was…

A: Given: Sample mean x¯=165 Sample standard deviation (s) = 45 Sample size (n) = 758 Confidence level…

Q: Assuming that the speed of all cars traveling on this highway have a normal distribution, construct…

A: Given Data : First we will calculate the mean and standard deviation of the sample provided :…

Q: In a survey, 26 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: According to the National Health Statistics Report, a sample of 360 one year old baby boys in the US…

A:

Q: For a fixed value of the standard deviation, a 95% confidence interval on the population mean will…

A:

Q: In an examination of purchasing patterns of shoppers, a sample of 16 shoppers revealed that they…

A: From the given information, sample mean, x̅=54 Population standard deviation, σ=21 Sample size n =16…

Q: A financial institution wishes to estimate the mean balances owed by its credit card customers. The…

A:

Q: A random sample of 51 four-year-olds attending day care centers provided a yearly tuition average of…

A:

Q: How large a sample should be selected to provide a 95% confidence interval with a margin of error of…

A:

Q: In a random sample of 15 ​people, the mean driving distance to work was 18.5 miles and the standard…

A:

Q: An employer claims that full time employees have a mean income of $35,000. A sample of 200 employees…

A: From the provided information, The hypotheses can be constructed as: Null hypothesis: H0: µ =…

Q: The local police department attempted to estimate average vehicle speeds along a strip of Main…

A: Standard error- is the standard deviation of its sampling distribution or an estimate of that…

Q: A college admissions officer takes a simple random sample of 96 entering freshmen and computes their…

A: We have to find out lower confidence interval...

Q: How large a sample should be selected to provide a 95% confidence interval with a margin of error of…

A: Given : Margin of error = 5 α = 0.05 Population standard deviation = σ = 30 zα2 = z0.052 = 1.96

Q: in a preliminary sample of men from a certain geographical region, the standard deviation of their…

A: Determine the sample size The sample size is obtained below as follows: The formula of sample size…

Q: Nine tests of a new jet engine yielded a mean thrust of 7600 pounds with a standard deviation of 90…

A: Given values, x¯=7600σ=90n=9z(95%)=1.96

Q: In a random sample of 12 people, the mean commute time to work was 30 minutes and the sample…

A:

Q: A researcher claims that the standard deviation of the number of deaths annually from typhoons in…

A:

Q: The tolerable level of a certain pollutant is 16 mg/l. A researcher takes a sample of size n=50, and…

A:

Q: In order to estimate the average electric usage per month, a sample of 81 houses was selected and…

A: Given datasample size , n =81Population S.D , σ =310For 90% CIP(-z<μ<z) = 0.90∴ z=1.645…

Q: How large a sample should be selected to provide a 95% confidence interval with a margin of error of…

A:

Q: If a light bulb manufacturing company wants to​ estimate, with 90​% confidence, the mean life of…

A: It is given that confidence level is 0.90, standard deviation is 1000 and margin of error E is 250.

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

A:

Q: In an effort to estimate the mean amount spent per customer for dinner at a major Atlanta…

A: From the provided information, Sample size (n) = 49 Population standard deviation (σ) = $5…

Q: An analyst is planning to estimate the mean of a quantitative variable using a 95% confidence…

A: Given that, Critical value: Using the z-table, the critical value at 95% confidence level is

Q: Calculate a 90% confidence interval for the mean of the population, supposed normal, from which…

A: Given, Heights 63 63 66 67 68 69 70 70 71 71 Let X be height of  animal…

Q: given a standard deviation of + or - 0.023m at the 90% confidence level, what is the 68% error level…

A: The confidence level of the data is 90%. The standard deviation of the data with error percentage is…

Q: How large a sample should be selected to provide a 95% confidence interval with a margin of error of…

A: Given that, Confidence Interval = 95% Margin of error, M.E. = 4 Population Standard deviation, σ =…

Q: During a natural gas shortage, a gas company randomly sampled residential gas meters in order to…

A: Solution: Let X be the gas consumption. From the given information, x-bar=250 cubic feet, S=50 cubic…

Q: According to the International Journal of Retail and Distribution Management(Vol. 39, 2011) survey…

A: Given, Margin error (E) = 0.25 Standard deviation = 1.41   The objective is to find the sample.…

Q: Find the margin of error for a​ 95% confidence interval for estimating the population mean when the…

A: Sample S.D = s = 110

Q: A community health plan wishes to estimate the mean number of visits per plan participant in a year.…

A: Given that Margin of Error, E = 2 Population SD = 6.3 Level of confidence = 0.95 The critical value…

Q: In a random sample of ten ​people, the mean driving distance to work was 23.2 miles and the standard…

A: Provided information is ; Sample size(n) =10  Mean(μ) = 23.2 Sample standard deviation(s) = 5.3…

Q: How large a sample should be used to provide a 95% confidence interval with a margin of error of 4,…

A:

Q: from a random sample of 36 business days from february 24, 2016, through february 24, 2017, the mean…

A: It is given that, Sample mean = 116.16. Population standard deviation, σ is 10.27. The sample size,…

Q: In developing patient appointment schedules, a medical center wants an estimate of the mean time…

A: Obtain the large sample size needed. The large sample size needed is obtained below as follows: Use…

Q: In a survey sample of 83 respondents, the mean number of hours worked per week is 39.04, with a…

A: Solution : The complete solution is given below in the attachment file.

Q: How large a sample should be selected to provide a 99% confidence interval with a margin of error of…

A:

Q: Suppose the population standard deviation is standard deviation "sigma"=7, an SRS of n=45 is…

A: Given that, σ=7,n=45 Critical value: Using the z-table, the critical value at 95% confidence level…

Q: In a random sample of twelve ​people, the mean driving distance to work was 18.8 miles and the…

A: From the given information we want to construct 90% confidence interval.

Q: In a random sample of eight cell​ phones, the mean full retail price was ​$431.50 and the standard…

A:

Q: average expenditure per student (based on average daily attendance) for a certain school year was…

A: Define the Null and alternative hypotheses:   Null Hypothesis:    H0: µ = 10,337.   Alternate…

Q: A fast-food franchiser is considering building a restaurant at a certain location. According to a…

A: Denote μ as the population mean number of pedestrians passing the location per hour.   It is needed…

Q: The national fire protection association reported that house fires in the United States result in…

A:

Q: Construct a 95% confidence interval for the population standard deviation σ if a sample of size 10…

A: Solution

Q: Assume that the heights of adult males (in inches) in the Sultanate of Oman are normally distributed…

A: The mean of the height of the male is 69.72 inches. The standard deviation of the height of the male…

Q: Given that you have a sample size of 10 different soda pops, with a sample mean of 2.228 and a…

A: The provided information are:

Q: From a random sample of 24 months from January 2006 through December 2016, the mean number of…

A: x¯=100σ=114n=24Confidence interval = 90%

Q: The standard deviation, S, for the annual medical cost of 24 households was found to equal $1689…

A: Suppose σ is the annual medical cost for all households.

Q: In a recent sample of 89 used cars sales costs, the sample mean was $6,225 with a standard deviation…

A: Given, Sample size = 89 Sample mean = 6225 Sample standard deviation = 3151   Since the population…

Q: A Research sampled 50 doctors to obtain a mean of 145,580 pesos, and standard deviation of 13,200…

A: The following data is given, Number of doctors (n) = 50, Mean income of the doctors (X¯) = 145,580,…

Q: In a random sample of 38 criminals convicted of a certain​ crime, it was determined that the mean…

A: Given : n= 38.0 , x= 67.0 s= 11.0 At 95.0 % confidence level , z score= 1.96

Q: A wildlife study is designed to find the mean weight of salmon caught by an Alaskan fishing company.…

A:

Q: How much do students pay, on the average, for textbooks during the first semester of college? From a…

A: Margin of Error (MoR): It is the Range of values that has the sample statistics in the confidence…

Q: Use this fact to derive an exact 95% confidence interval for the population variance o?.

A: