A sample of 200 smokers were asked at what age they started smoking. The sample mean was18.3 years with a standard deviation of 4.35 years. Construct a 95% confidence interval for the mean age thatall smokers begin smoking. Please show all your work.

Q: In a sample of 226 Americans, the mean annual sugar consumption was 148 pounds with a standard…

A: The sampling distribution of a sample mean follows a normal distribution with the mean converging…

Q: A random group of 36 people in Toms River were asked “how much money did you spend at the grocery…

A: Given: Sample mean x¯=149.50 Sample size (n) = 36 Sample standard deviation (s) = 22.50 Confidence…

Q: A researcher has collected the blood samples of 29 individuals and found that the mean hemoglobin…

A: Obtain the 95% confidence interval for the mean hemoglobin concentration for the population. The 95%…

Q: A study was commissioned to find the mean weight of the residents in certain town. The study…

A: Confidence interval : Confidence interval is a range of values it contains the true population…

Q: In a survey, 28 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: In a survey, 15 people were asked how much they spent on their child's last birthday gift. The…

A: Given: n=15,σ=$10,α=1-0.9=0.1

Q: The heights of a random sample of 20 college students showed a mean of 174.5 centimeter: and a…

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

Q: A sample of 200 smokers were asked at what age they started smoking. The sample mean was 18.3 years…

A: From the given information, Sample size = 200 Sample mean = 18.3 Sample standard deviation = 4.35…

Q: the standard deviation of the 16 observations was 0.95 inches (again, the sample mean was 17.2).…

A: Given :  Standard deviation of the 16 observations was 0.95 inches & the sample mean was 17.2.…

Q: A researcher has collected the blood samples of 35 individuals and found that the mean hemoglobin…

A:

Q: A physician wanted to estimate the mean length of time  that a patient had to wait to see him after…

A: Given: Formula used: For confidence interval

Q: The average weight of 36 randomly selected school buses was 4150 pounds with a standard deviation of…

A: Given data,x=4150σ=480n=36z-value at 99% confidence is Zc=2.576

Q: If a sample of 4 fish from my pond has mean weight 157 grams with a standard deviation of 8.3 grams…

A: Solution: Let X be the weight of fish in my pond. From the given information, n=4, x-bar = 157…

Q: The lead levels in a random sample of 35 crows in the region were measured and recorded. The mean…

A:

Q: An investigator conducts a study to investigate whether there is a difference in mean PEF in…

A:

Q: A study was commissioned to find the mean weight of the residents in certain town. The study…

A: Given: n=58, x=174 and s=38. Now,Degrees of freedom=n-1=58-1=57 Then, at 95% confidence level, the…

Q: An investigator wants to estimate caffeine consumption in high school students. How many students…

A:

Q: The mean amount of the 812 mortgages taken out in a city in the past year must be estimated. Based…

A: Given : Population S.D (σ) = 20000 Confidence Level = 95% Margin of error (E) = 2000

Q: The heights of a random sample of 50 college students showed a mean of 68.5 inches and standard…

A:

Q: A study of 100 apple trees showed that the average number of apples per tree was 2000.  The standard…

A:

Q: An irate student complained that the cost of textbooks was too high. He randomly surveyed 36 other…

A: Given that,x¯=121.60,σ=6.36,n=36 Critical value: By using the z-tables, the critical value at 10%…

Q: A random sample of 1000 google play apps was collected and the average rating was calculated to be…

A:

Q: A group of statistics students decided to conduct a survey at their university to find the average…

A: Given: The sample number of students are n=240. The sample mean amount of time students spent…

Q: In a sample of 31 students, the mean scholarship amount received was $562, with a standard deviation…

A: Given data,n=31x=562s=17.04df=n-1=30α=0.10t-critical value at α=0.10 and df=30 is tc=1.697

Q: A study of 25 graduates of four-year public colleges revealed the mean amount owed by a student in…

A: It is given that the mean amount owed by a student in student loans is $55,051. The sample standard…

Q: In a poll of 27 students, 65% ±6% were in favor of increasing the amount of time between classes.…

A: From the provided information, Sample size (n) = 27 65% ± 6% were in favour of increasing the amount…

Q: A study by the department of education of a certain state was trying to determine the mean SAT…

A: From the provided information, Sample size (n) = 77 Mean score (x̅) = 515 Standard deviation (s) =…

Q: A research engineer for a chip manufacturer is investigating chip life for their new 7 nanome- ters…

A:

Q: A sample of Alzheimer's patients are tested to assess the amount of time in stage IV sleep. It has…

A:

Q: An investigator conducts a study to investigate whether there is a difference in mean PEF in…

A: Introduction:The 100 (1 – α) % confidence interval for the population mean, μ, for given sample…

Q: A physician wanted to estimate the mean length of time  that a patient had to wait to see him after…

A: Solution: Let X be the waiting time. From the given information, x-bar=30 minutes, s=9 minutes and…

Q: A study of 81 bolts of carpet showed that their average length was 77.5 yards. The standard…

A:

Q: The lead levels in a random sample of 23 crows in the region were measured and recorded. The mean…

A:

Q: A study of 96 bolts of carpet showed that their average length was 77.5 yards. The standard…

A: GivenMean(x)=77.5sample size(n)=96standard deviation(s)=1.6α=1-0.99=0.01α2=0.005zα2=z0.05=2.58

Q: Suppose that the owner of a recently opened convenience store in Kuala Lumpur, Malaysia, wants to…

A: Given: n=16x¯=75s=6

Q: A study was commissioned to find the mean weight of the residents in certain town. The study…

A:

Q: A study of a local high school tried to determine the mean amount of money that each student had…

A: The sample size is n= 42 which is large.  And mean is X bar = 3800 Standard deviation, sigma= 600…

Q: A group of 40 bowlers showed that their average score was 192 with a standard deviation of 8. Find…

A: Given: n = 40 x¯ = 192 σ = 8 confidence level = 95%

Q: A sample of 50 patients undergoing chemotherapy has a mean weight loss of 24 kg after they went the…

A: For the given data Find 99% confidence interval = ?

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: An advertising agency that manages a major radio station wants to estimate the mean amount of time…

A: Determine the sample size needed.   Obtain the critical value of z at the 95% confidence level.…

Q: A random sample of 90 group leaders, supervisors, and similar personnel revealed that a person spent…

A:

Q: A study by the department of education of a certain state was trying to determine the mean SAT…

A: Solution: Let X be the score. From the given information, x-bar=448, s=84 and n=56.

Q: Estimate the average number of feathers that a mature tom turkey has with 90% confidence interval by…

A: It is an important part of statistics . It is widely used .

Q: A study of a local high school tried to determine the mean number of text messages that each student…

A:

Q: In a random sample of 2500 men being treated for obesity, the mean total cholesterol level is 175…

A:

Q: In a sample of 45 students, the mean scholarship amount received was $854, with a standard deviation…

A:

Q: Suppose a random sample of 50 baksetball players showed the average height to be 78 inches. Also…

A:

Q: The average salary of 64 employee was 5400. Using historical data, we will assume that the…

A: Given: n= 64.0 , x̄= 5400.0 σ= 280.0 At 95.0 % confidence level , z score= 1.96

Types of Bias

Statistics is the study of data collection, organization, analysis, interpretation, and presentation. Statistical bias is a characteristic of a statistical technique or its findings in which the expected value deviates from the actual root quantitative parameter being estimated. According to the actual definition of bias, it refers to the tendency of a statistic to overestimate or underestimate a parameter.