# A 95% confidence level for the difference between u1 and u2 runs from -2 to +6. From this we can infer that a. u1 is probably greater than u2. b. u1 is probably less than u2. c. there may be

20,590 questions
1. ## Statistics

A 95% confidence level for the difference between u1 and u2 runs from -2 to +6. From this we can infer that a. u1 is probably greater than u2. b. u1 is probably less than u2. c. there may be no difference at all between u1 and u2. d. the difference between

asked by Kevin on April 30, 2014
2. ## Statistics

A 95% confidence level for the difference between u1 and u2 runs from -2 to +6. From this we can infer that a. u1 is probably greater than u2. b. u1 is probably less than u2. c. there may be no difference at all between u1 and u2. d. the difference between

asked by Kevin on May 1, 2014

3. Determine the t-critical value for a two-sided confidence interval in each of the following situations. a. Confidence level = 95%, df = 15 b. Confidence level = 99%, n = 5. c. Confidence level = 95%, n = 15 d. Significance level = 0.01, df = 37

asked by Lizzie on March 25, 2015
4. ## math help

Consider the following. (Give your answers correct to four decimal places.) (a) Determine the level of confidence given the confidence coefficient z(á/2) for z(á/2) = 1.65. Incorrect: Your answer is incorrect. . (b) Determine the level of confidence

asked by Tommy8 on June 22, 2013
5. ## math help

Please help me on these I have lost the tables that I would need to answer them or at least the ones I think are used. Consider the following. (Give your answers correct to four decimal places.) (a) Determine the level of confidence given the confidence

asked by Tommy7 on June 22, 2013
6. ## math

Consider the following. (Give your answers correct to four decimal places.) (a) Determine the level of confidence given the confidence coefficient z(á/2) for z(á/2) = 1.65. Incorrect: Your answer is incorrect. . (b) Determine the level of confidence

asked by Sue 8 on June 21, 2013
7. ## math

Consider the following. (Give your answers correct to four decimal places.) (a) Determine the level of confidence given the confidence coefficient z(á/2) for z(á/2) = 1.65. Incorrect: Your answer is incorrect. . (b) Determine the level of confidence

asked by JACKIE on June 22, 2013
8. ## statistics

Pleas HeLp!!!!!!!!!! A random sample of the test scores of 100 applicants for college entry at a large junior college showed a mean score of 72.6. Determine a 99%, 95%, and 90% confidence interval for the m mean score of all applicants at the junior

asked by courntey on September 17, 2011
9. ## statistics

You intend to estimate a population proportion with a confidence interval. The data suggests that the normal distribution is a reasonable approximation for the binomial distribution in this case. While it is an uncommon confidence level, find the critical

asked by Denise on July 26, 2017
10. ## Statistics

We have calculated a 95% confidence interval for a proportion and would prefer the confidence interval to be more precise, that is narrower. Using the same sample, we can narrow the confidence interval using which of the following? A) increasing the

asked by Nick on October 27, 2013
11. ## Statistics

Compare the 95% and 99% confidence intervals for the hours of sleep a student gets. Explain the difference between these intervals and why this difference occurs. 95% confidence intervals: 6.214, 7.686 99% confidence intervals: 5.944, 7.956

asked by Hope on October 5, 2011
12. ## Statistics

Compare the 95% and 99% confidence intervals for the hours of sleep a student gets. Explain the difference between these intervals and why this difference occurs. 95% confidence intervals: 6.214, 7.686 99% confidence intervals: 5.944, 7.956

asked by Hope on October 5, 2011
13. ## Statistics

The standard deviation for a population is σ = 15.3. A sample of 36 observations selected from this population gave a mean equal to 74.8. a) Make a 90% confidence interval for μ b) Construct a 95% confidence interval for μ. c) Determine a 99% confidence

asked by ---- on November 21, 2013
14. ## Statistics

Use the sample data and confidence level to construct the confidence interval estimate of the population p....n=5200, x=4821, 99% confidence

asked by Tangee on May 1, 2013
15. ## Chemistry

[4 points] In a recent poll, 10 local students were asked how many beers they drink in a typical week. The responses, in no particular order, were: 4, 10, 6, 14, 12, 17, 30, 15, 12, 0 At a 90% confidence level, is there an outlier in the data given above?

asked by Alex on April 7, 2010
16. ## statistics

1. Suppose the estimate of a proportion of a normal population is to be within 0.05 using the 95% confidence level. How large a sample is required if: a. It is known from previous studies that p = 0.3? b. There is no prior knowledge of p? 2. Each of the

asked by Micheal on March 31, 2015
17. ## Statistics 7

A doctor wants to estimate the HDL cholesterol of all 20 to 29 year old females. How many subjects are needed to estimate the HDL cholesterol within 2 points with 99% confidence assuming s-17.8 based on earlier studies. Suppose the doctor would be content

asked by Megan on May 5, 2013
18. ## Statistics (45)

In developing patient appointment schedules, a medical center wants to estimate the mean time that a staff member spends with each patient. How large a sample should be taken if the desired margin of error is two minutes at a 95% level of confidence? How

asked by Mia on May 6, 2014
19. ## Statistics

Use the sample data and confidence level to construct the confidence interval estimate of the population proportion p. n=500, x=350, 90% confidence ?

asked by Rob on April 30, 2013
20. ## Math: Statistics

Determine the smallest sample size required to estimate the population mean under the following specifications: a. e = 2.4 confidence level = 80% data between 50 and 150 d. e = 1.2 confidence level = 90%, data between 25 and 175

asked by Isis MArtin on August 26, 2012
21. ## math

hypothesis testing , this is the example, The company has enjoyed success, and has grown to the current staff of 26 people. There is a perception/rumor in the company that the average pay rate for males is different than the average pay rate for females.

asked by yan on April 14, 2018
22. ## Elementary Statistics

1) Construct a confidence interval of the population proportion at the given level of confidence. x=60,n=300, 99% confidence. The 99% confidence interval is (_,_) 2) A researcher wishes to estimate the proportion of adults who have high-speed internet

asked by Erin on June 6, 2012

A doctor wants to estimate the HDL cholesterol of all 20-29 year old females. How many subjects are needed to estimate the HDL cholesterol within 2 points with 99%confidence assuming s=17.8 based on earlier studies? Suppose the doctor would be content with

asked by Megan on May 5, 2013
24. ## statistics

1) A group of scientists created 150 trials to measure whether electric shock treatment could cure paranoid delusions. Of these trials, 52 were successful. Find the margin of error E that corresponds to a 95% confidence level. The critical value for 95%

asked by Shawnie on June 14, 2011
25. ## Statistics

A group of scientists created 150 trials to measure whether electric shock treatment could cure paranoid delusions. Of these trials, 52 were successful. Find the margin of error E that corresponds to a 95% confidence level. The critical value for 95%

asked by Thomas on June 15, 2011
26. ## Statistics

A group of scientists created 150 trials to measure whether electric shock treatment could cure paranoid delusions. Of these trials, 52 were successful. Find the margin of error E that corresponds to a 95% confidence level. The critical value for 95%

asked by Eric on June 6, 2011
27. ## Sociology Research Methods

What is a confidence level? What is the confidence interval? Write a sentence that could appear in a research report that would exemplify a confidence interval.

asked by Faye on June 24, 2017
28. ## statistics

Refer to Table 1 in the article “Snail Shells in a Practical Application of Statistical Procedures” in the Electronic Reserve Readings. Find the margin of error, E, with a confidence interval of your choosing (50-99%). What is the significance of

asked by len on April 26, 2012
29. ## math

THERE ARE ESTIMATES OF THE MARGIN OF ERROR FOR CONFIDENCE LEVELS OTHER THAN 95%. FOR A 90% CONFIDENCE LEVEL AND A SAMPLE SIZE N, THE MARGIN OF ERROR IS APPROXIMATELY 82/N%.SUPPOSE WE WISH TO HAVE A MARGIN OF ERROR OF 1% WITH A 90% CONFIDENCE LEVEL.

asked by saRA on December 19, 2016
30. ## Statistics

When estimating a population mean μ, where the population standard deviation σ is known, we can: a. choose a larger z value, construct a wider confidence interval, and achieve a lower confidence level b. choose a smaller z value, construct a narrower

asked by Melanie on November 14, 2012
31. ## statistics

which of the following statements is true? Justify your answer with an example. i)When the margin of error is small, the confidence level is high. ii)When the margin of error is small, the confidence level is low. iii)A confidence interval is a type of

asked by johnprabhakaran on November 15, 2011
32. ## statistics

Using the 95% level of confidence, what is the confidence interval for the proportion of households represented at a town meeting

asked by Jay on April 21, 2014
33. ## statistics

Find the critical value zc necessary to form a confidence interval at the given level of confidence. a. 90% = 1.645 b. 85% = 1.8025

asked by looking for someone to varify my work please on April 1, 2010
34. ## Statistics

If, for a given sample size, 10% of all possible confidence intervals do not contain the unknown population parameter value, what is your confidence level?

asked by Anonymous on February 19, 2016
35. ## Statistics

How would I find the confidence level (in %) if I am given the standard deviation, size of the random sample, and confidence interval?

asked by C on April 3, 2013
36. ## Math

How would I find the confidence level (in %) if I am given the standard deviation, size of the random sample, and confidence interval?

asked by C on April 3, 2013
37. ## statistics

Each of the following is a confidence interval for u = true average(population mean) resonance frequency (Hz) for all tennis rackets of a certain type: (114.4, 115.6) (114.1, 115.9) A) What is the value of the sample mean resonance frequency? B) Both

asked by joe on November 23, 2012
38. ## statistics

Each of the following is a confidence interval for u = true average(population mean) resonance frequency (Hz) for all tennis rackets of a certain type: (114.4, 115.6) (114.1, 115.9) A) What is the value of the sample mean resonance frequency? B) Both

asked by joe on November 23, 2012
39. ## statistics

10. Using the results of a Newsweek poll conducted in March of 2009, a 90% confidence interval on the proportion of adult Americans who have a favorable opinion of Barack Obama is given by (0.699, 0.741). If everything else is the same, but the confidence

asked by ali awan on May 8, 2013
40. ## statistics

A confidence interval or significance test is called stable if the confidence level or P-value does not change very much when the conditions for use of the procedure are violated

asked by A confidence interval or significance test is call on April 6, 2011
41. ## statistics

Discuss the effect that the confidence level has upon the confidence interval.

asked by MissPatte on November 20, 2014
42. ## statistics

Determine the level of the confidence given the confidence coefficient z(α/2) for the following situation: z(α/2) = 1.96

asked by slomomo on February 27, 2015
43. ## MATH....

Determine the level of the confidence given the confidence coefficient z(α/2) for the following situation: z(α/2) = 1.96

asked by Jen on November 3, 2011
44. ## math

With a confidence level of .95 and a confident interval of 5 and a population of 20,000 what is the sample size? With a confidence level of .99 and a confident interval of 5 and a population of 20,000 what is the sample size? Finally, using the sample size

asked by sam on October 15, 2007

2. Each of the following is a large-sample confidence interval for μ, the mean resonance frequency (HZ) for all tennis rackets of a certain type. (114.4, 115.6), (114.1, 115.9) a. What is the value of the sample mean resonance frequency? b. Both intervals

asked by Lizzie on March 25, 2015
46. ## Statistics

63.4 65.0 64.4 63.3 54.8 64.5 60.8 49.1 51.0 Assume that these observations are an SRS from the late Cretaceous atmosphere. What is the mean percent of nitrogen in ancient air with a 90% confidence level? Hint: uses one-sample t confidence

asked by Dawn on August 21, 2010
47. ## statistics

Use the given confidence level and sample data to find a confidence interval for the population standard sigma. Assume that a simple random sample has been selected from a population that has a normal distribution. salaries of college graduates who took a

asked by rich on December 29, 2011
48. ## statistics

Help!!!!!! A confidence interval estimate for the population mean is given to be (39,90, 48.11) If the standard deviation is 11.473 and the sample size is 52 determine the maximum error of the estimate. determine the confidence level used for the given

asked by amy on November 9, 2011
49. ## Satatstics

Assume that a random sample is used to estimate a population proportion p. find the margin of errror E that corresponds to the given statistics and confidence level n= 550, x=165, 90%confidence

asked by Heather on November 16, 2007
50. ## statisics

What is the confidence level of each of the following confidence intervals for u? x+/-1.96(o/SR N) ht t p : / / w w w . a l l i a n t h a w k . o r g / i m a g e s / C ON F I D e n c e _i nt e r v a l _ n o_ b ac k g r o u n d . g i f it looks like that,

asked by ginger on March 1, 2013
51. ## STATISTIC

A study based on a sample of size 25 reported a mean of 94 with a margin of error of 15 for 95% confidence (a) Give the 95% confidence interval. (__________,________) (b) If you wanted 99% confidence for the same study, would your margin of error be

asked by YOMO on May 28, 2017
52. ## Math

Given the following statistical list: 13,17,19,22,25,27,29,29,32,and 33. Assuming a desired "Confidence Level" of 95%, find the confidence interval for the above scores. 19.8 < u(mean)< 29.4 14.6 < u < 33 13.4 < u < 22.7 11.1 < u < 18.5 I have 2 weeks to

53. ## statistics

sing the 95% confidence level and the 11th grade male writing scores in the Class Data file, you would expect the lower end of the confidence interval to be approximately what value?" Answer

asked by Anonymous on November 26, 2012
54. ## math

A score of 243 is a "basic" reading level. Scores for a random sample of 3000 students had a xbar = 250 with a standard error 1.0 The 99% confidence interval for the mean score all students in the city is 247.4 to 252.6. Ques: Is there good evidence that

55. ## statistics

A sample of 200 students in a English class were asked- How long did you sleep last night? sample mean: 6.4 hours S.D. = 1.6 HOURS Standard Error = .11 hours sample size = 200 What type of data is used in this example? my answer: MEASUREMENT DATA What

asked by Sheri on July 9, 2012
56. ## Statistics

Should companies use the same confidence interval each time a confidence interval is determined or should the level change based on situations? If it changes based on situations, what type of situations might call for higher confidence levels?

asked by John on April 6, 2012
57. ## M A T H

WORD PROBLEM: Tims tet grades in french were: 86,96,88,91 what score must Tim make on his next test to average 92? a 89 b 93 c 97 d 99 I said 99. because when you add all numbers its 460/5 = 92 2) the water level indicator measures the rise and fall in

asked by MAX on October 6, 2011
58. ## math questions

WORD PROBLEM: Tims tet grades in french were: 86,96,88,91 what score must Tim make on his next test to average 92? a 89 b 93 c 97 d 99 I said 99. because when you add all numbers its 460/5 = 92 2) the water level indicator measures the rise and fall in

asked by Mitch on October 6, 2011
59. ## Statistics

When consumers apply for credit, their credit is rated using the FICO score. A bank manager used a random sample of the credit scores of 18 customers and determined the following 95% confidence interval: (613.6, 708.0) If the sample used 45 customers

asked by Katelyn on November 6, 2013
60. ## math

A score of 243 is a "basic" reading level. Scores for a random sample of 3000 students had a xbar = 250 with a standard error 1.0 The 99% confidence interval for the mean score all students in the city is 247.4 to 252.6. Ques: Is there good evidence that

61. ## statistics

5. What happens to the width of our confidence interval for m if we increase the sample size but keep the confidence level the same? A) It increases. B) It decreases. C) It stays the same. D) It depends on the sample mean and standard deviation.

asked by ali awan on May 8, 2013
62. ## statistics

what happens to the width of our confidence interval for mu if we increase the sample size but keep the confidence level the same ? a. it increases b. it stays the same c. it decreases d. it depends on the sample mean and standard deviation

asked by jen on December 6, 2011
63. ## statistics

use SPSS to calculate the 90%, 95% and 99% confidence intervals for the mean of the variable weight. Interpret the three confidence intervals in terms of whether there is a significant difference between the mean of the sample and a hypothesized mean of

asked by love on June 29, 2014
64. ## RES 341

A sample of 300 is taken and the sample mean is computed to be 7.65 and the sample standard deviation is 5. Assume the data is ratio level. Compute the 95% confidence interval on the mean. Compute the 3.9% confidence interval on the mean Which confidence

asked by Meh on October 16, 2010
65. ## Statistics

Thirty-three small communities in Connecticut (population near 10,000 each) gave an average of x = 138.5 reported cases of larceny per year. Assume that σ is known to be 42.9 cases per year. (a) Find a 90% confidence interval for the population mean

asked by Amy on December 3, 2016
66. ## statistics

Please help- A random sample of n=500 households where 150 have combined cable,phone, and internet service. Firrst, calculate p-hat, the sample proportion of households having such service. Then use a confidence level for pi, the proportion of all

asked by Sandra on November 13, 2013
67. ## STATISTICS

Which of the following would increase the width of a confidence interval? Changing from a 99% to 95% confidence level. Increasing the variability of the outcome. Increasing the sample size. Removing an outlier from the data

asked by Susie on August 6, 2013
68. ## STATISTICS

Which of the following would increase the width of a confidence interval? Changing from a 99% to 95% confidence level. Increasing the variability of the outcome. Increasing the sample size. Removing an outlier from the data

asked by Susie on August 7, 2013
69. ## make check

Consider the following. (Give your answers correct to four decimal places.) (a) Determine the level of confidence given the confidence coefficient z(á/2) for z(á/2) = 1.65. Incorrect: Your answer is incorrect. . 0.90 is what I got and it was wrong, I

asked by Tom 84 on June 18, 2013
70. ## QNT351

use a 95% confidence interval to estimate the difference between the population means. Interpret the confidence interval. random sample 390 x1 5258 s1 152 x2 5220 s2 192

asked by Terri on September 27, 2012
71. ## statistics

What is the mathematical relationship between the confidence level and the level of significance, α? Can you explain this to me in an easy to understand way? Thank you

asked by MissPatte on September 11, 2014
72. ## Statistics

In hypothesis testing, as the a level gets smaller, the level of confidence increases. True or False? And why or why not?

asked by Nina on July 30, 2014
73. ## Statistics

Find the minimum sample size that should be chosen to assure that the proportion estimate p will be within the required margin of error, .06. Use a 95% confidence interval and a population proportion of .7. The critical value for a 95% confidence level is

asked by Eric on June 6, 2011
74. ## math

assume that a sample is used to estimate a population proportion p. find the margin of error E that corresponds to the given statistics and confidence level. 98% confidence, the sample size is 780, of which 40% are successes what does that mean in English?

asked by daniel on July 22, 2012
75. ## Stats

2) Find the minimum sample size that should be chosen to assure that the proportion estimate p will be within the required margin of error, .06. Use a 95% confidence interval and a population proportion of .7. The critical value for a 95% confidence level

asked by Eric on June 14, 2011
76. ## stastics

Assume that a random sample is used to estimate a population proportion p. Find the margin of error E corresponds to the given statistics and confidence level. 90% confidence, the sample size is 1457, of which 30% are successes.

asked by anonymous on November 16, 2013
77. ## statistics

Are Chicken based dishes more populat than Pizza to a level which is statistically significant at the 95% confidence level? What figures do i have to look at to work it out? Thanks

asked by Lauren on March 25, 2013
78. ## Stastics

Which of the following descriptions of confidence intervals is correct? (Select all that apply) a. If a 95% confidence interval contains 0, then the 99% confidence interval contains 0 b. If a 99% confidence interval contains 0, then the 95% confidence

asked by Lindsay on April 25, 2016
79. ## Algebra 2

A simple random sample of 90 is drawn from a normally distributed population, and the mean is found to be 138, with a standard deviation of 34. What is the 90% confidence interval for the population mean? Use the table below to help you answer the

asked by Jasmine on December 9, 2014
80. ## Statistics

Hoping to lure more shoppers downtown, a city builds a new parking garage in the central business district. The city hopes that the parking revenues will pay for the garage. During a recent two month period (44 days), the city statistician calculated the

asked by Katie on November 10, 2013
81. ## maths

Data were collected on the differences in weight gains of 12 people one month after they stopped smoking, compared with their weight at the time when they stopped smoking. The data are given in Table 2. A positive quantity corresponds to a gain in weight,

asked by mary on March 30, 2016
82. ## statistics

The Frayed Nerves Anxiety Scale (FNAS) is used to measure the anxiety level of people on a scale from 0 to 1000. Four students were randomly chosen and given the FNAS before their second exam. Their scores were 700, 653, 740, and 707. The standard

asked by Anand on October 17, 2011

1. The average life expectancy of people around the world is 71.30 years with a population standard deviation of 8.00 years. I take a sample of 50 countries now and find that the average life expectancy is 74.37 years. Suppose I’m interested in seeing if

asked by amanda on November 7, 2016
84. ## statistics

In a sample of 100 steel wires the average breaking strength is 50 kN, with a standard deviation of 2 kN. a. Find a 95% confidence interval for the mean breaking strength of this type of wire. b. An engineer claims that the mean breaking strength is

asked by Don't get it!! :( on October 29, 2011
85. ## algebra

The sample size needed to estimate the difference between two population proportions to within a margin of error E with a confidence level of 1- alpha can be found by using the equation shown below. Replace n1 and n2 by n and solve for n. E= z alpha/2

asked by Mario on October 30, 2013
86. ## Statistics

Answer the question Yes or No. Sam computed a 90% confidence interval for from a specific random sample of size n. He claims that at the 90% confident level, his confidence interval does not contain . Is this claim correct? Answer a. No b. Yes

asked by Desperate on July 7, 2012
87. ## uog

A survey of an urban university (population of 25,450) showed that 750 of 1100 students sampled attended a home football game during the season. What inferences can be made about student attendance at football games? Using the 90% level of confidence, what

asked by samantha on March 25, 2011
88. ## statistic

For a given month, a random sample of 30 sales girls from a superstore has a sample mean of salary of RM 800 with standard deviations of RM 140. Estimate the mean monthly salary for all employees using the 95% confidence interval.(what does mean of 95%

asked by niki on September 27, 2011
89. ## chemistry

A manometer attached to a flask contains NH3 gas have no difference in mercury level initially as shown in diagram. After the sparking into the flask, it have difference of 19 cm in mercury level in two columns. Calculate % dissociation of ammonia. (1) 21%

asked by Anonymous on May 5, 2013
90. ## Statistics

1. In developing patient appointment schedules, a medical center wants to estimate the mean time that a staff member spends with each patient. Using a value for the population standard deviation of eight minutes, determine: a. How large a sample should be

asked by JYD on October 27, 2008
91. ## Statistics- Math

Assume that a random sample is used to estimate a population proportion p. Find the margin of error E that corresponds to the given statistics and confidence level. n=550 x= 220, 90% confidence The margin of error E = (round to four decimal places)

92. ## statistics

You intend to estimate a population proportion with a confidence interval. The data suggests that the normal distribution is a reasonable approximation for the binomial distribution in this case. Find the critical value that corresponds to a confidence

asked by robyn on July 22, 2012
93. ## statistics

A teacher wants to compare the mean geology scores of two different classes. She is testing the null hypothesis that there is no difference in the population mean scores of the two classes. The difference of the sample means is 51.4. If the standard

asked by bobert on July 7, 2014
94. ## Stasticstics/math

A teacher wants to compare the mean geology scores of two different classes. She is testing the null hypothesis that there is no difference in the population mean scores of the two classes. The difference of the sample means is 51.4. If the standard

asked by Gabby on October 14, 2014

I cannot figure this our for the life of me!Assume that the gross national debt initially is equal to \$3 trillion and the federal government then runs a deficit of \$300 billion. What is the new level of gross national debt? What happens to the amount of

asked by queenie on August 10, 2009
96. ## chemistry

help needed in drawing the diagram to show how hydrogen has numerous spectral lines I also need help with this question.... ---------------- ---------------- ---------------- ---------------- ---------------- -------------------- Each line above represents

asked by ruby on February 6, 2007
97. ## Statistics

Assume that a random sample is used to estimate a population proportion p. Find the margin of error E that corresponds to the given statistics and confidence level. 95% confidence the sample size is 2096 of which 25%are successes The margin of E= (round to

asked by Rob on April 30, 2013
98. ## HUMAN RELATIONS, PART 1

.The main reason self-confidence is important in human relations is because A. self-confidence makes you seem more interesting to other people. B. self-confidence makes you appear important in the eyes of other people. C. the alternative to self-confidence

asked by Rumonge on December 9, 2008
99. ## Human Relations Part 1

The main reason self-confidence is important in human relations is because A. self-confidence makes you seem more interesting to other people. B. forming relationships involves risk. C. self-confidence makes you appear important in the eyes of other

asked by tazkiyah30 on February 6, 2014
100. ## Res.

A two-tailed hypothesis test at the 5 percent level of significance (£\ = .05) is exactly equivalent to asking whether the 95 percent confidence interval for the mean includes the hypothesized mean. If the confidence interval includes the hypothesized

asked by mel on July 14, 2010