A survey of 29 smokers showed that they smoke an average of 13 packs per week....

A survey of 29 smokers showed that they smoke an average of 13 packs per week. If the data follows a normal distribution with a standard deviation of 3 packs per week, find the 99% confidence interval for the true average of packs smoked per week.

Expert Solution

We have given that,

Sample mean =13   packs per week.
Sample standard deviation =3 packs per week.
Sample size =29
Level of significance=1-0.99=0.01
Degree of freedom =28

t critical value is (by using t table)=2.763

Confidence interval formula is

=(11.46, 14.54)


Lower confidence limit=11.46 packs per week.

Upper confidence limit=14.54 packs per week.

orchestra answered 1 year ago

A survey of 10 smokers showed that they smoke an average of 13 packs. the data...

A survey of 10 smokers showed that they smoke an average of 13 packs. the data follows a normal distribution, with a previous record of standard deviation as 3 packs per week. find the 95% confidence interval for the true average of packs smoked per week. What is the sample mean value? Which distribution is used in this case? What is the Maximal Margin of Error? What is the confidence interval?

A survey of 29 sugar addicts showed that they eat 13 jumbo candy bars a week....

A survey of 29 sugar addicts showed that they eat 13 jumbo candy bars a week. If the trend follows a typical normal distribution with a standard deviation of 3 candy bars a week, find the 99% confidence interval for the true average amount of candy bars eaten per week.

A survey on the number of hours a college student works per week showed that the...

A survey on the number of hours a college student works per week showed that the hours varied from 5 to 61 where 5 was the lowest number and 61 was the highest number. Determine the class width, classes, class marks and class boundaries of a frequency distribution table if the work hours were grouped using 8 classes. You can make a table to help you do this. Note: there is no frequency column.

In 2003 a survey of 35,000 adults showed that 26% were smokers. In 2010 a survey...

In 2003 a survey of 35,000 adults showed that 26% were smokers. In 2010 a survey of 45,000 adults showed that 21% were smokers. Construct a 95% confidence interval for the true difference between proportions. a) (4.41% , 5.59%) b) (3.33% , 6.67%) c) (4.82% , 5.18%) d) (3.83% , 6.17%)

The research firm conducted a survey to determine the average mean amount of money smokers spend...

The research firm conducted a survey to determine the average mean amount of money smokers spend on cigarettes per week. A sample of 19 smokers reveals a mean and standard deviation of $20 and $5 respectively. find the intercept the 99% confidence interval for the mean.

A survey conducted by the American Automobile Association showed that a family of four spends an average of $215.60 per day while on vacation.

A survey conducted by the American Automobile Association showed that a family of four spends an average of $215.60 per day while on vacation. Suppose a sample of 64 families of four vacationing at Niagara Falls resulted in a sample mean of $252.45 per day and a sample standard deviation of $76.50. (a) Develop a 95% confidence interval estimate of the mean amount spent per day in dollars by a family of four visiting Niagara Falls. (Round your answers...

Kate’s survey showed that 54 of 120 employees eat fast food at least once a week...

Kate’s survey showed that 54 of 120 employees eat fast food at least once a week for lunch. What is the proportion of employees who eat fast food at least once a week, using a 98% confidence interval? Group of answer choices 24% to 44% 30% to 50% 34% to 56% 28% to 45%

{Exercise 3.29 (Algorithmic)} The results of a national survey showed that on average, adults sleep 6.9...

{Exercise 3.29 (Algorithmic)} The results of a national survey showed that on average, adults sleep 6.9 hours per night. Suppose that the standard deviation is 1 hours. Round your answers to the nearest whole number. Use Chebyshev's theorem to calculate the percentage of individuals who sleep between 4.9 and 8.9 hours. At least % Use Chebyshev's theorem to calculate the percentage of individuals who sleep between 3.9 and 9.9 hours. At least % Assume that the number of hours of...

Suppose 31 pregnant women are sampled who smoke an average of 22 cigarettes per day with...

Suppose 31 pregnant women are sampled who smoke an average of 22 cigarettes per day with a variance of 144.00. a) What is the probability that the pregnant women will smoke an average of 20 cigarettes or more? probability = b) What is the probability that the pregnant women will smoke an average of 21 cigarettes or less? probability = c) What is the probability that the pregnant women will smoke an average of 18 to 24 cigarettes? probability =...

Do engineers work more hours per week than the national average hours per week worked? ...

Do engineers work more hours per week than the national average hours per week worked? [ Choose ] Two-sided test One-sided lower test One-sided upper test Is the gas mileage of a smart for two coupe really less than 40 mpg? (According to the 2013 EPA gas mileage figures, the answer is yes. Doesn't seem that smart…) [ Choose ] Two-sided test ...

Question