week-10-practice-quiz-with-explanation-and-correct-answer

Pop. Mean Stand. Dev. Sample size 1 73.00 10.00 6.00 14 2 62.50 8 1.Independent random samples are selected from two populations. Below are selected summary statistics. (a) Construct the 95% confidence interval for μx-µY. (b) Obtain the P-value for the alternative µx =µY.

Hello! I need help with the following stats questions. 1. What is a confidence interval? 2. What is a confidence coefficient? 3. What do statisticians mean by the term accuracy?

10. Student A in our class ECON 2210 tried to estimate the average marks of the midterm held in March, 2022. Based on a random sample of 30 students' marks and with a 95% confidence level, the student arrived at an interval estimate for the average marks of between 50 and 80. (a) After receiving this result, student B in the same class claimed that there was a 95% chance that the true average marks of the midterm were between 50 and 80. How would you respond to this statement? Is it correct? Why or why not? (b) Student C in the same class did not agree with student B and he claimed that there was a 95% chance that the true average marks of the next midterm were between 50 and 80. How would you respond to this statement? Is it correct? Why or why not?

b) A small-town mechanic says that 8% his customers come in for an oil change. When 1000 samples were drawn from his records, it was found that 6.5% of these came in for an oil change. What is the target population? Does the value 8% refer to the parameter or to the statistic? Is the value 6.5% a parameter or a statistic? i. ii. iii.

Supposed a study using a random sample of postgraduate students in Sydney found that the average amount of time spent using a mobile phone per day is 5.5 hours. Indicate whether the quantity described above is a population parameter or a sample statistic, and write down the notation.      Hints: You may type in how you read the notation, instead of using the symbol itself. E,g. you can write "mu" or "xbar" or "phat" or "rho" or "sigma" for the Greek alphabet or special symbol.

A teacher gave the same test to two classes. In the class with 50 students, the mean score was 75. In the class with 30 students, the mean was 83. What was the mean score for all students?

Also find the p value and test statistic

Suppose you apply an estimator to sample data and you get an estimate of 5 forwhatever sample you draw from the population. Is this estimator the most efficient because itsvariance is zero? Why or why not?

1. The manager at Bell's Gym wants to know the proportion of members who use the Cardio Machines. A sample of 260 members showed that 40 of them use cardio machines. Calculate a 97% confidence interval for the proportion of members who use the cardio machines.

Focusing on government spending as a percentage of GDP in the U.S., we observed that between 1820 and 1929 the: minimum value was 3.13%; mean value was 6.83%; and maximum value was 29.03%. In contrast, between 1930 and 2021 , the a) None of the above answers are correct. B) maximum value was 10.94%.c) minimum value was 2.12%. D) mean value was 30.56%. Note:- Do not provide handwritten solution. Maintain accuracy and quality in your answer. Take care of plagiarism. Answer completely. You will get up vote for sure.

(Ch8) True or False? With a given sample, when we lower the confidence level, it will reduce the width of a confidence interval of the population proportion.

18 We can make a confidence interval more precise (narrower) by, a increasing the sample size.       b reducing the confidence level.       c increasing the confidence level.       d both (a) and (b) are correct.

Population Sample 35 30 24 32 32 28 35 31 34 20 24 24 26 29 32 35 32 37 35 Using sample data determine the Sample Mean?

X1=80  X2=180 A=400  B=200

Ca = 40 + 0.80 (Y-T) Ig = 30 Xn= 10 T=20 G=20 DI-Y-T

The birthweight (in kg) of 55 babies are tabulated in the frequency distribution below: Birthweight (kg) Class Midpoint Frequency M (1– 1.5| (1.5-2 1.25 6. 1.75 10 (2- 2.5) 2.25 1 (2.5-3) 2.75 15 10 (3-3.5] 3.25 3. (3.5- 4) 3.75 55 Total Calculate the relative frequency of the class interval (2 - 2.5).

a) For each, find the expressions for marginal utilities and the marginal rate of substitution, and determine whether monotonicity and convexity are met.

Is it true or false that the least absolute deviations (LAD) estimator minimizes the sum of the absolute value of the population errors.

Question 1 The distance between the sample mean and the true population is the sampling error, O True False

If the t-statistic for a variable is -1.74, is the variable statistically significant? O No O Yes

10. 7 students were asked how many pencils they had. The responses were 2, 5, 8, 3, 1, 6, and 4. a. Calculate the sample mean 8. Find the sample standard deviation C Find the Q1, Q3, and the interquartile range.

K The first statistics exam had a mean of 71 and a standard deviation of 15 points; the second had a mean of 82 and a standard deviation of 5 points. Anna scored a 84 on both tests. Megan scored 94 on the first exam and 74 on the second. They both totaled 168 points on the two exams, but Anna claims that her total is better. Explain. The total of Anna's z-scores is, which is greater than Megantotal of (Round to one decimal place as needed.)

Manufacturers of tires report that car tires should be able to last an average of 50,000 miles. A new tire company produces a different type of tread and tests 100 randomly selected tires. This sample of 100 tires lasted an average of 51,500 miles. Assuming the new type of tread does not improve the mileage of the tire, 200 sample means were simulated and displayed on the dotplot. Simulated Tire Mileage +++ +++H 47,000 48,000 49,000 50,000 51,000 52,000 53,000 Mean mileage Using the dotplot and the sample mean mileage, is there convincing evidence that the new type of tread improves the mileage of the tire? Yes, because a mean mileage of 51,500 or more occurred only 14 out of 200 times, the mean mileage is statistically significant. There is convincing evidence the new type of tire tread improves mileage of the tire. Yes, because a mean mileage of 51,500 or less occurred 186 out of 200 times, the mean mileage is statistically significant. There is convincing evidence the new type of…

see image below. i=120, ii=35, iii=135, iv=6

Question: In a certain factory there are two independent processes manufacturing the same item. The average weight in a sample of 250 items produced from one process is found to be 120 ozs. with a standard deviation of 12 ozs. while the corresponding figures in a sample of 400 items from the other process are 124 and 14. Obtain the standard error of difference between the two sample means. Is this difference significant ? Also find the 99% confidence limits for the difference in the average weights of items produced by the two processes respectively.

What are the Confidence Intervals for the Population Mean?

Question 3 A car company wants to know the monthly sales made in ($000), based on the brand of vehicle. The data collected was entered on a MINITAB spreadsheet for analysis. Exhibit II below was subsequently generated.   Exhibit 2     Model N Mean Median Tri.Mean Std Dev S.E. Mean Hyundai 23 109 135 107.64 * 1.34 Toyota 27 165 124 143.65 9.5 **   You are required to test at the 5% level of significance the hypothesis that the average monthly earnings on Hyundai Vehicles is equal to $110,000 versus the alternative that it is different from $110,000.   Complete the following: i. Give the null and alternative hypothesis of this test. ii. Determine the critical value(s) of this test. iii. Compute the value of the test statistic. iv. State the decision rule. v. Give your decision based on the available sample evidence. vi. Hence, state your conclusion.

QUESTION 8 Having an extreme score in a sample (outliers) will NOT effect which of the following?     standard deviation     mean     mode     variance

2. The SAT scores for 12 randomly selected senior high school students are: 1221 1342 1298 987 786 1439 671 1299 1020 1380 889 1157 a.) sample mean = b.) s²= c.) s = d.) Are the SAT scores normally distributed (Explain Why)? YES or NO e.) Construct and interpret a 95% confidence interval for the mean SAT score.

A publisher reports that 50%50% of their readers own a particular make of car. A marketing executive wants to test the claim that the percentage is actually different from the reported percentage. A random sample of 240240 found that 45%45% of the readers owned a particular make of car. Determine the P-value of the test statistic. Round your answer to four decimal places.

Question 4 of 10, step Calculate the margin of error of a confidence interval for the difference between two population means using the given information. Round your answer to six decimal places e, 14. n, 88 ₂ 10.72, ny71.c 0.95

G. Thumb, the leading salesperson for the Moe D. Lawn Landscaping Company, turned in the following summary of sales for the week of October 23–28: Date              No. of Clients Oct. 23   13         Oct. 24   8         Oct. 25   10         Oct. 26   15         Oct. 27   10         Oct. 28   22         Find the mean, median, and mode. (If an answer does not exist, enter DNE.) mean      clients median      clients mode      clients