On the Standford-Binet test, the mean IQ is 100. A class of 21 kindergarten pupils were tested with a resulting mean of 94 and a standard deviation of 9.12. What is the margin of error of the 90% confidence interval of the average IQ of the kindergarten pupils?

Q: Researchers found that in certain counties in the country, females spend an average of 65 days in…

A: standard deviationσ=4n=36x¯=65

Q: A random group of 36 people in Toms River were asked “how much money did you spend at the grocery…

A: Given: Sample mean x¯=149.50 Sample size (n) = 36 Sample standard deviation (s) = 22.50 Confidence…

Q: The caffeine content (in mg) was examined for a random sample of 50 cups of black coffee dispensed…

A: Given sample size of black coffee cups n = 50Caffeine content mean = 110mgStandard deviation = 7.1…

Q: According to a recent poll of eight social networking sites, the average monthly visitor count was…

A: In question, Given that a recent poll of eight social networking sites, the average monthly visitor…

Q: A sample of 56 Charleston County households have a mean income of $27,519 with a standard deviation…

A:

Q: A student wanted to construct a 99% confidence interval for the mean age of students in her…

A: Solution:From the given information, number of students is 9 and confidence level is 99%, sample…

Q: A while ago, I asked n=44 of my students in a stats class to estimate the number of pages in a book…

A:

Q: In a survey, 45 people were asked how much they spent on their last partners birthday gift. The…

A: Given information- Sample size, n = 45 Significance level, α = 0.10 Sample mean, x-bar = $90 Sample…

Q: he average weight of 20 randomly selected cars was 3500 pounds. The sample standard deviation was…

A: given data, n=20df=n-1=20-1=19x¯=3500 pounds s=315 pounds CI=0.90α=1-0.90=0.10

Q: The mean number of English courses taken in a two-year time period by male and female college…

A: Answer:-

Q: A study was commissioned to find the mean weight of the residents in certain town. The study…

A: Given: n=58, x=174 and s=38. Now,Degrees of freedom=n-1=58-1=57 Then, at 95% confidence level, the…

Q: From the scores in subject statistics for 8 students, it was found that the mean score is 73 and the…

A: We have given that,  Sample mean (x̄) = 73,  standard deviation (s) = 5.15 and sample size (n) = 8…

Q: Michelle takes a sample of 25 different-gender married couples. In her sample, she found that the…

A:

Q: The heights of a random sample of 50 college students showed a mean of 68.5 inches and standard…

A:

Q: The lead levels in a random sample of 35 crows in the region were measured and recorded. The mean…

A: It is given that  Sample size n = 35 Sample mean M = 4.50 Sample SD s = 1.12 Confidence level = 99%…

Q: A study analyzed the body fat percentage of 80 ISU students. The sample mean was 23.70 and the…

A:

Q: find the 99% confidence interval of the mean number of miles driven per day by all truckers

A: It is given that  Average = 540 Population standard deviation = 40 Sample size = 90

Q: Are low-fat diets or low-carb diets more effective for weight loss? A sample of  77  subjects went…

A: Given that  Given that    Sample sizes n1=77      , n2=79        Sample means X̄1= 4.7     , X̄2=2.6…

Q: 73 full time workers were surveyed on how many hours they spend watching television during the week.…

A: Given information, n=73x¯=3.2s=0.2 Confidence level is 95% significance level is 5% df=n-1=73-1=72 t…

Q: A sample of 77 subjects went on a low-carbohydrate diet for six months. At the end of that time, the…

A: Given that  Sample size n1=77 , n2=79 Sample means x1=4.7 , x2=2.6 s1=7.16 , s2=5.9

Q: A survey was conducted that asked 1004 people how many books they had read in the past year. Results…

A: From the provided information, Sample size (n) = 1004 Sample mean (x̅) = 10.4 books Sample standard…

Q: A sample of 14 commuters in Chicago showed the average of the commuting times was 33.2 minutes. If…

A: Given that x bar =33.2.s.d =8.3,n=14,alpha=.05

Q: From a random sample of 64 high school seniors, the sample mean and standard deviation of the math…

A: Given,mean(x)=90standard deviation(s)=7sample size(n)=64α=1-0.92=0.08α2 =0.04degrees of freedom…

Q: According to a study of 90 truckers, a trucker drives, on average, 560 miles per day.  If the…

A:

Q: Sam is the manager of a used clothing store.  He wants to estimate the average amount a customer…

A: From the provided information, The population standard deviation is not known therefore t…

Q: The average entrance exam score of a random sample of 35 freshmen students is 89.66 with a standard…

A: Given,sample size(n)=35sample mean(x)=89.66standard deviation(s)=18.28degrees of…