A city planner wants to estimate the average monthly residential water usage in the city. He selected a random sample of 37 households from the city, which gave the mean water usage to be 3410.30 gallons over a one-month period. Based on earlier data, the population standard deviation of the monthly residential water usage in this city is 387.60 gallons. Make a 95 % confidence interval for the average monthly residential water usage for all households in this city.

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: One measure of physical fitness is the amount of time it takes for the pulse rate to return to…

A: Confidence interval for population mean: Confidence interval for population mean is the range of…

Q: a 99% confidence interval

A: Confidence interval :  Confidence interval measures the degree of uncertainty. or it is the…

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: In a survey, 24 people were asked how much they spent on their child's last birthday gift. The…

A: Since population standard deviation is unknown, Use t-distribution to find t-critical value. Find…

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

A: Since population standard deviation is unknown, Use t-distribution to find t-critical value. Find…

Q: One measure of physical fitness is the amount of time it takes for the pulse rate to return to…

A: X=16.5n=20S=3.55CI will be X±tα2,n-1*Sn

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

A: Given,sample mean(x¯)=38.9population standard deviation(σ)=9.6sample…

Q: In a survey, 23 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: In a survey, 23 people were asked how much they spent on their child's last birthday gift. The…

A: We have given that  Sample size=n=23 Mean=mu=37 Standard deviation=S=4 90% confidence level

Q: The operations manager of a large production plant would like to estimate the average amount of time…

A: Given information- Population standard deviation, σ = 7 minutes So, in seconds- Population standard…

Q: In a survey, 12 people were asked how much they spent on their child's last birthday gift. The…

A: Determine the best point estimate of the population mean. The best point estimate of the population…

Q: In a survey, 13 people were asked how much they spent on their child's last birthday gift. The…

A: Given, Sample size, n = 13 Sample mean = 44 Sample standard deviation, s = 10 Confidence level = 80%…

Q: In a survey, 30 people were asked how much they spent on their child's last birthday gift. The…

A: We have given that,  Sample mean (x̄) = $ 44, standard deviation (s) = $ 10, sample size (n) = 30…

Q: In a survey, 20 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: A poll conducted randomly in 2014 found that 52% of U.S. adult Twitter users get at least some news…

A: Proportion is 0.52. The standard error 0.024 The absolute value of Zα/2 is 2.5758 using the Excel…

Q: Marcelina has over 500 songs on her mobile phone, and she wants to estimate the average length of…

A:

Q: In a survey, 22 people were asked how much they spent on their child's last birthday gift. The…

A: Solution: From the given information, confidence level is 0.80, σ=$10 and n=22.

Q: A student conducted a study and reported that the 95% confidence interval for the population mean…

A:

Q: In a survey, 23 people were asked how much they spent on their child's last birthday gift. The…

A: Since population standard deviation is unknown, use t-distribution to find t-critical value. Find…

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

A: Solution: From the given information, S=2 and n=15. The confidence level is 0.98.

Q: In a survey, 19 people were asked how much they spent on their child's last birthday gift. The…

A: From the given information, there are 19 people with the sample mean is $49 and the sample standard…

Q: A researcher constructed a 95 percent confidence interval for the mean number of alfalfa weevils on…

A: The 95% confidence interval for the population mean is (1.50, 3.50)

Q: In a survey, 30 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: wish to construct a 99% confidence interval

A: Given that  Sample size (n) =14 Mean money spent (x¯ )= $145 = Sample mean  Sample standard…

Q: The operations manager of a large production plant would like to estimate the average amount of time…

A: Since we know population standard deviation, use z-distribution to find z-critical value. Find…

Q: In a survey, 14 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: The operations manager of a large production plant would like to estimate the average amount of time…

A:

Q: In a survey, 30 people were asked how much they spent on their child's last birthday gift. The…

A: Given ,Sample size n = 30Sample mean x = 36Sample standard deviation (s0 =2d.F = n-1dF = 30-1 =…

Q: Construct a 90% confidence interval for the true average monthly salary earned by all employees of…

A:

Q: In a survey, 20 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: In a survey, 30 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: In a survey, 10 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: In a survey, 14 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: To determine the views of students on a particular campus about fraternities, an 11-point attitude…

A:

Q: A marine biologist is interested in whether the Chinook salmon, a particular species of salmon in…

A: Confidence Interval: Confidence interval is the interval estimate of the population parameter. It is…

Q: It is no surprise that the US has the highest calorie intake of any country in the world. Suppose a…

A:

Q: In a survey, 23 people were asked how much they spent on their child's last birthday gift. The…

A: Givensample size(n)=23sample mean (x) = 31standard deviation (s) = 8α = 1-0.95=0.05α2=0.025degrees…

Q: The operations manager of a large production plant would like to estimate the average amount of time…

A: Since we know population standard deviation, use z-distribution to find z-critical value. Find…

Q: ne hundred (900) high school freshmen were randomly selected for a national survey. Among survey…

A: Given data,Mean x=2.7sd     σ=0.4n=900What is the margin of error at 95% confidence level?

Q: A random sample of 328 medical doctors showed that 171 had a solo practice. Let p represent the…

A: Given, The best point estimate for p is,

Q: A bank wishes to estimate the mean balances owed by customers holding MasterCard. The population…

A: Determine the sample size n needed.   Obtain the critical value of z at the 98% confidence level.…

Q: The population standard deviation for the height of college basketball players is 3 inches. If we…

A: Given information: Population standard deviation for the height of college basketball players σ=3…

Q: In a survey, 19 people were asked how much they spent on their child's last birthday gift. The…

A: The summary of the statistics is, The degree of freedom is, df=n-1   =19-1   =18 Critical value: By…

Q: A sociologist is comparing the proportion of teenage boys who receive a text message at least once…

A: The  Conditions for the Confidence interval for the difference in population proportions • Samples…

Q: The operations manager of a large production plant would like to estimate the average amount of time…

A: Given :  s = 6 minutes = 6*60 = 360 seconds E = 18 seconds Confidence level = 91%

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

A:

Q: In a survey, 20 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: A nutritionist wants to estimate the average caloric content of the burritos at a popular…

A:

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.