Refer to Exhibit 8-1. If the sample mean is 9 hours, then the 95% confidence interval...

Refer to Exhibit 8-1. If the sample mean is 9 hours, then the 95% confidence interval is approximately

Exhibit 8-1: In order to estimate the average time spent on the computer terminals per student at a local university, data were collected from a sample of 81 business students over a one-week period. Assume the population standard deviation is 1.2 hours.

a. 7.04 to 110.96 hours

b. 7.36 to 10.64 hours

c. 7.80 to 10.20 hours

d. 8.74 to 9.26 hours

Solutions

Expert Solution

Solution :

Given that,

Point estimate = sample mean = = 9

Population standard deviation = =1.2

Sample size n =81

At 95% confidence level the z is ,

= 1 - 95% = 1 - 0.95 = 0.05

/ 2 = 0.05 / 2 = 0.025

Z/2 = Z0.025 = 1.96 ( Using z table )

Margin of error = E = Z/2 * ( / $\sqrt$ n)
= 1.96 * ( 1.2 / $\sqrt$ 81)

= 0.26
At 95% confidence interval estimate of the population mean
is,

- E < < + E

9 - 0.26 < < 9+ 0.26

8.74 < < 9.26

d. 8.74 to 9.26 hours

orchestra answered 1 year ago

Next > < Previous

Related Solutions

Refer to the accompanying data set and construct a 95% confidence interval estimate of the mean...

Refer to the accompanying data set and construct a 95% confidence interval estimate of the mean pulse rate of adult females; then do the same for adult males. Compare the results. Males : 86. 76. 49. 61. 55. 63. 53. 73. 53. 61. 74. 59. 63. 76. 85. 68. 63. 94. 41. 84. 74. 64. 69. 72. 55. 68. 58. 78. 69. 66. 64. 94. 56. 66. 60. 57. 68. 72. 87. 60. Females: 81. 91. 60. 68. 57. 81....

Refer to the accompanying data set and construct a 95% confidence interval estimate of the mean...

Refer to the accompanying data set and construct a 95% confidence interval estimate of the mean pulse rate of adult females; then do the same for adult males. Compare the results. Males Females 84 80 77 97 52 60 59 65 51 55 59 79 52 78 75 85 50 86 65 59 70 34 62 68 65 85 76 74 79 75 65 63 68 68 99 81 44 62 86 64 70 82 67 85 70 68 71...

Refer to the accompanying data set and construct a 95% confidence interval estimate of the mean...

Refer to the accompanying data set and construct a 95% confidence interval estimate of the mean pulse rate of adult females; then do the same for adult males. Compare the results. Males Females 84 78 71 95 49 56 63 64 53 54 61 82 51 81 75 88 54 89 62 57 69 36 59 65 62 86 78 74 80 75 65 64 65 68 94 77 45 61 86 61 71 82 63 83 74 68 74 ...

Refer to the accompanying data set and construct a 95% confidence interval estimate of the mean...

Refer to the accompanying data set and construct a 95% confidence interval estimate of the mean pulse rate of adult females; then do the same for adult males. Compare the results. Males Females 84 81 72 97 51 56 62 67 55 54 64 81 51 78 79 87 53 86 63 56 71 37 59 67 63 84 81 77 85 78 64 61 65 67 96 81 45 58 89 65 69 85 64 81 71 70 70 ...

Construct a 95% confidence interval for an experiment that found the sample mean temperature for a...

Construct a 95% confidence interval for an experiment that found the sample mean temperature for a certain city in August was 101.82, with a population standard deviation of 1.2. There were 6 samples in this experiment. A group of 10, foot - surgery patients had a mean weight of 240 pounds. The sample standard deviation was 25 pounds. Find a confidence interval for a sample for the true mean weight of all foot – surgery patients. Find a 95% Confidence...

2. What is the sample size, n, for a 95% confidence interval on the mean, if...

2. What is the sample size, n, for a 95% confidence interval on the mean, if we know that the process’ standard error is 3.2 units, and we want to allow at most 1.0 units for our error? 3. Let’s say that you just randomly pulled 32 widgets from your production line and you determined that you need a sample size of 46 widgets, However, you get delayed in being able to pull another bunch of widgets from the line...

The 95% confidence interval for the mean, calculated from a sample of size n = 25...

The 95% confidence interval for the mean, calculated from a sample of size n = 25 is 2.233163 ≤ μ ≤ 3.966837 . Determine the sample mean X ¯ = (round to the first decimal place). Assuming that the data is normally distributed, determine the sample standard deviation s = (round to the first decimal place)

q1) The 95% confidence interval for the mean, calculated from a sample is 1.412011 ≤ μ...

q1) The 95% confidence interval for the mean, calculated from a sample is 1.412011 ≤ μ ≤ 2.587989. Determine the sample mean X-(this one x dash) = q2) Assuming that the data is normally distributed with the population standard deviation =1.5, determine the size of the sample n =

14. A researcher estimates the 95% Confidence Interval for a sample (n=100) with a mean of...

14. A researcher estimates the 95% Confidence Interval for a sample (n=100) with a mean of M=3. The population mean and standard deviation are known as 2.5±2 (µ±σ). What is the upper confidence limit for this interval? A) 0.392 B) 1.96 C) 2.608 D) 3.392 E) There is not enough information to answer this question.

Forma a 95% confidence interval on the mean pouring temperature for iron castings if a sample...

Forma a 95% confidence interval on the mean pouring temperature for iron castings if a sample of size 25 yielded a mean of 2560 and a standard deviation (s) of 20.

Subjects