In a study of factors affecting hypnotism, visual analogue scale (VAS) sensory ratings were 16 subjects. For these sample ratings, the mean is 8.33 with a standard deviation of 1.96. Co 99% confidence interval for the true mean sensory ratings

Q: Suppose, according to a 1990 demographic report, the average U. S. household spends $90 per day.…

A: Sample mean = $84.5.Sample standard deviation, s is $14.5.The sample size, n is 30.

Q: A quality control manager wants to be sure that the standard deviation of oil containers is below a…

A: Let Xi be the amount of oil in the ith container,i=1,2,...,n.

Q: A sample of 49 managers reveals a sample mean of $45,420. The standard deviation of the samp is…

A: As the population standard deviation is not known, we will use t-distribution. The number of degrees…

Q: We take a sample of 50 people and obtain a sample mean of 147 pounds with a standard deviation of 15…

A: We have given that  Sample size n = 50 Sample mean = 147 Standard deviation = 15 90%confidence…

Q: In a study investigating the average salaries of employees in a company, 36 employees of the company…

A: Solution: Given information: n=36 Sample size  x=2400  Sample mean s= 1200 Sample standard deviation…

Q: In a survey, 26 people were asked how much they spent on their child's last birthday gift. The res…

A: The summary of statistics is, x¯=31,s=4,n=26 The degree of freedom is, df=n-1   =26-1   =25 Critical…

Q: In a survey, 26 people were asked how much they spent on their child's last birthday gift. The…

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Q: In a survey, 25 people were asked how much they spent on their child's last birthday gift. The…

A: The provided information are:

Q: In a survey, 13 people were asked how much they spent on their child's last birthday gift. The…

A: GivenMean(x)=42standard deviation(s)=7sample size(n)=13

Q: The mean for the verbal component of the SAT is reported as 500, with a standard deviation of 100. A…

A: It is given that the sample mean is 498 and the population standard deviation is 100.

Q: In a survey, 23 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: In a sample of 40 water specimens taken from a construction site 26 contained detectable level of…

A: According to the provided information, sample size (N)=40 number of favorable cases (X) = 26 The…

Q: in a preliminary sample of men from a certain geographical region, the standard deviation of their…

A: Determine the sample size The sample size is obtained below as follows: The formula of sample size…

Q: The average of serum cholesterol levels in a group of 20 Lebanese was 210 mg/dl and the Standard…

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Q: a chemist analysis an iron ore for FeO.and obtained value of 12.35% with a standard deviation of…

A: Given:Sample size, n=4Confidence level=95%

Q: Why do you need to consider the studentized version of x to develop a confidence-interval procedure…

A: We consider the studentized version of x to develop a confidence-interval procedure for a population…

Q: In a survey, 10 people were asked how much they spent on their child's last birthday gift. The…

A: We have given that,  Sample size (n) = 10, sample mean (x̄) = $34 and standard deviation (s) = $6…

Q: Question 1 In a test of weight loss programs, 40 adults used a new weight loss product. After a…

A:

Q: A random sample of 100 observations produced a mean x̅ =38.5 and a standard deviation of 3.2. find a…

A: Given information Sample size(n) = 100 Sample mean x̅ =38.5 Sample standard deviation = 3.2…

Q: Find the 90 percent confidence interval for the variance and standard deviation for the time it…

A: Solution :  Given : n = 27             s = 8.9 minutes             α = 0.1 Confidence interval for…

Q: In a questionnaire, a random sample of students were asked whether they studied for more than four…

A: The known values are, Critical values: By using the z-table, the critical value at 99.7% confidence…

Q: In a survey, 23 people were asked how much they spent on their child's last birthday gift. The…

A: Since population standard deviation is unknown, use t-distribution to find t-critical value. Find…

Q: A pizza shop owner wishes to find the 99% confidence interval of the true mean cost of a large plain…

A: Given σ=0.14E=0.11n=?The z-value at 99% confidence is 2.58

Q: What sample size would be needed to estimate the average body temperature of humans if you wished to…

A: Given data,E=0.1z-value at 99% confidence is Zc=2.576σ=0.6n=?

Q: A study of 64 bolts of carpet showed that their average length was 75 yards. The standard deviation…

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Q: A researcher is interested in the decrease in adolescent BMI after a new after school program is…

A:

Q: An analyst is planning to estimate the mean of a quantitative variable using a 95% confidence…

A: Given that, Critical value: Using the z-table, the critical value at 95% confidence level is

Q: Consider a group of 27 patients in an experiment who received a placebo. At the beginning of the…

A:

Q: In a survey, 30 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: A survey of 31 accountants shows the average salary is $65,000 with a population std deviation of…

A: Given : Sample size, n= 31 Mean = $65000 Population standard deviation = 7000

Q: In a sample of 90 large grade A eggs, the mean number of calories was 70 with a standard deviation…

A:

Q: In a survey, 25 people were asked how much they spent on their child's last birthday gift. The…

A: Given that, Sample size (n) = 25 Sample mean (x̄) = $41 Sample standard deviation (s) = $9 5%…

Q: In a survey, 27 people were asked how much they spent on their child's last birthday gift. The…

A: The mean is $36 and the standard deviation is $6.

Q: How large a sample should be used to provide a 95% confidence interval with a margin of error of 4,…

A:

Q: To find the standard deviation of the diameter of wooden dowels, the manufacturer measures 19…

A:

Q: In a survey, 23 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: Two sets of chromium analyses were performed on water samples from a stream that runs near a…

A: Given: Two sets of chromium analyses were performed on water samples from a stream that runs near a…

Q: In a survey, 19 people were asked how much they spent on their child's last birthday gift. The…

A:

Q: Suppose the population standard deviation is standard deviation "sigma"=7, an SRS of n=45 is…

A: Given that, σ=7,n=45 Critical value: Using the z-table, the critical value at 95% confidence level…

Q: 1.A factory has a machine that dispenses 80ml of fluid in a bottle. An employee believes the average…

A: Given Sample size, n=40Sample mean, x¯=78Sample sd, s=2.5CL=95%

Q: A 95% confidence interval for the mean hours freshmen spent on social media per day was calculated…

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Q: average expenditure per student (based on average daily attendance) for a certain school year was…

A: Define the Null and alternative hypotheses:   Null Hypothesis:    H0: µ = 10,337.   Alternate…

Q: In a study it was found out of a random sample of 30 there was a sample standard deviation of 2.4.…

A:

Q: A sample data set, n = 115, shows human body temperatures with a mean of 99.6ºF. If the standard…

A: Given Data: n=115x¯=99.6σ=0.75   z-value corresponding to 99% Confidence Interval=2.576

Q: In a survey, 21 people were asked how much they spent on their child's last birthday gift. The…

A: Margin of error is the error due to random sampling. The margin of error decreases with increase in…

Q: In a recent sample of 89 used cars sales costs, the sample mean was $6,225 with a standard deviation…

A: Given, Sample size = 89 Sample mean = 6225 Sample standard deviation = 3151   Since the population…

Q: The determination of copper in a seawater sample gave a mean value of 77.81 mg/L and a ndard…

A: Critical value: The confidence level is 100*(1–α)% = 95%. The critical value is obtained as 1.96…

Q: In a sample of 100 steel canisters, the mean wall thickness was 8.1 mm with a standard deviation of…

A:

Q: In a previous example, your sample consisted of 83 respondents. Suppose you doubled your sample size…

A: Introduction -  Confidence interval  CI=x±zsn