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Confidence intervals
Page 3
Questions (711)
Students took n = 35 samples of water from the east basin of Lake
Macatawa and measured the amount of sodium in parts per
3 answers
asked by
Alex
856 views
A university dean wishes to estimate the average number of hours his part-time instructors teach per week. The standard
4 answers
asked by
bob
4,302 views
1. Past experience indicates that the variance, ¦Ò2x, of the scores, X, obtained on the verbal portion of a test is 5,625.
3 answers
asked by
Tian
570 views
A statistics practitioner would like to estimate a population mean to within 50 units with 99% confidence given that the
4 answers
asked by
Tom
1,892 views
Biologists studying the healing of skin wounds measured the rate at which new cells closed a razor cut made in the skin of an
3 answers
asked by
Natasha
1,699 views
There are 250 computer programmers employed at Computers.com, Inc. A sample of 50 programmers revealed that 30 graduated with a
3 answers
asked by
Ann
301 views
Confidence interval Concept Check
1 point possible (graded) As in the previous section, let X1,…,Xn∼iidexp(λ) . Let
1 answer
asked by
Sammu
653 views
Construct a 90% confidence interval for the population mean. Assume the population has a normal distribution. A same of 15
4 answers
asked by
S
3,132 views
A simple random sample of students is selected, and the students are asked how much time they spent
preparing for a test. The
4 answers
asked by
Brian
1,417 views
A random sample of 50 households in community A has a mean household income of X- =Rs. 44,600 with a standard deviation s =Rs.
3 answers
asked by
Faheem
841 views
An accelerated life test on a large number of type-D alkaline batteries revealed that the mean life for a particular use before
7 answers
asked by
Ryan
1,850 views
A random sample of 150 towns in a western state had a mean annual precipitation of 2.86 inches. Assume that the population
3 answers
asked by
Kathy
1,049 views
given the following information, determine the 68.3 percent, 95.5 percent, and 99.7 percent confidence intervals. Mean = 4.33,
2 answers
asked by
Anonymous
751 views
I am having a lot of trouble with these questions can anyone help me please.
2. On September 2, 2004, a Dan Jones poll based on a
3 answers
asked by
penelope
714 views
ten randomly selected people were asked how long they slept at night. The mean time was 7.1 hours and the (sample) standard
3 answers
asked by
Asia
1,765 views
Lorraine was in a hurry when she computed a confidence interval for μ. Because σ was not known, she used a Student's t
3 answers
asked by
jr
4,299 views
Suppose a random sample of 36 is selected from a population with a standard deviation of 12. If the sample mean is 98, the 99%
3 answers
asked by
mona
2,226 views
Compare the results to those obtained in part a how does increasing the level of confidence affect the size of the margin of
3 answers
asked by
Wanda
88 views
Construct a 99% confidence interval about if the sample size n is 34 lower bound upper bound
3 answers
asked by
Wanda
99 views
Construct a 95% confidence interval about if the sample size is 34
3 answers
asked by
Wanda
101 views
Construct a 95% confidence interval about null if the sample size n is 34 lower bound
Upper bound
3 answers
asked by
Wanda
105 views
Suppose the following data are selected randomly from a population of normally distributed values.
40 51 43 48 44 57 54 39 42 48
1 answer
asked by
Mama
244 views
The weight of luggage that a randomly selected airline passenger brings onto a flight has a mean of 35 lbs and a standard
4 answers
asked by
Allie
678 views
A large school district would like to estimate the mean score for all of its 5th grade students on a certain mathematics
2 answers
asked by
ella
648 views
A health care professional wishes to estimate the birth weights of infants. The standard deviation of the birth weights is known
4 answers
asked by
Api
1,166 views
A random sample of 16 mid-sized cars tested for fuel consumption gave a mean of 26.4 kilometers per liter with a standard
3 answers
asked by
Kapaki Katea
904 views
Forty-nine items are randomly selected from a population of 500 items. The sample mean is 40 and the sample standard deviation
1 answer
asked by
myke
799 views
A Today/CNN/Gallup Poll of 1015 adults found that 13% approved of the job Congress was doing in 1995. Find the 95% confidence
2 answers
asked by
CJ
649 views
A filling machine is designed to fill soda bottles with 16 ounces of soda. The distribution for the weight of the bottles is
3 answers
asked by
Leo Elvis
941 views
Construct a 99% confidence interval for the population mean, ì. Assume the population has a normal distribution. A group of 19
3 answers
asked by
Anonymous
1,261 views
use SPSS to calculate the 90%, 95% and 99% confidence intervals for the mean of the variable weight. Interpret the three
2 answers
asked by
love
757 views
Assume that a standardized test is designed to have the mean score of 100 and the standard deviation of 15. At the 95%
3 answers
asked by
virginia
571 views
A simple random sample of 60 items resulted in a sample mean of 96. The population standard deviation is 16.
a. Compute the 95%
5 answers
asked by
Mia
1,518 views
The average cost per night of a hotel room in New York City is $273 (SmartMoney, March 2009). Assume this estimate is based on a
3 answers
asked by
Vanessa
586 views
A study of 60 bolts of carpet showed that their average length was 180 yards. The standard deviation of the population is 6
3 answers
asked by
hassan
499 views
A food manufacturer samples 7 bags of pretzels off the assembly line and weighs their contents. If the sample mean is 14.2 oz
3 answers
asked by
Anonymous
1,022 views
Explaining confidence. A student reads that a 95% confidence interval for the mean ideal weight given by adult American women is
3 answers
asked by
Mimi
2,525 views
Given the following information, determine the 68.3 percent, 95.5 percent, and 99.7 percent confidence intervals.
overbar above X
3 answers
asked by
Anonymous 11/24/13
499 views
Exercise 8.92
Tony's Pizza guarantees all pizza deliveries within 30 minutes of the placement of orders. An agency wants to
3 answers
asked by
----
2,252 views
A study of generator related carbon monoxide deaths showed that a sample of 6 recent years had a variance of 16.8 deaths per
4 answers
asked by
Elise
2,265 views
The U.S. Dairy Industry wants to estimate the mean yearly milk
consumption. A sample of 16 people reveals the mean yearly
4 answers
asked by
Jan
1,349 views
1.
Are there more broken bones in summer or winter? We get records about the number of fractures treated in January and July at a
3 answers
asked by
Katie
748 views
1. A study of 40 people found that they could do on the average15 pull ups with a standard deviation of .6. Find the 99%
4 answers
asked by
Anonymous
1,937 views
A study of 420,048 cell phone users found that 135 of them developed cancer of the brain or nervous system. prior to this study
3 answers
asked by
Rob
2,572 views
Suppose x has a mound-shaped distribution with sigma = 9 . A random sample of size 36 has sample mean 20. Is it appropriate to
3 answers
asked by
Steph
1,044 views
For each of the following confidence intervals, indicate how much of the distribution would be placed in the cutoff region for a
3 answers
asked by
jerry
848 views
A random sample of 250 men yielded 175 who said they'd ridden a motorcycle at some time in their lives, while a similar sample
3 answers
asked by
John
493 views
Answer the question Yes or No. Sam computed a 90% confidence interval for from a specific random sample of size n. He claims
4 answers
asked by
Desperate
3,088 views
1) Construct a confidence interval of the population proportion at the given level of confidence.
x=60,n=300, 99% confidence. The
3 answers
asked by
Erin
2,087 views
A sample of 352 subscribers to Wired magazine shows the mean time spent using the Internet is 13.4 hours per week, with a sample
4 answers
asked by
Annette
1,303 views
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Parent Categories (55)
Biostatistics
Data Analysis
Data Analysis and Interpretation
Data Analysis and Sampling
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