A pollster wishes to estimate the number of left-handed scientists. How large a sample isneeded in order to be 90% confident that the sample proportion will not differ from thetrue proportion by more than 4.5%? A previous study indicates that the proportion of left-handed scientists is 7.05%.

Q: The use of the Internet is constantly growing. How many randomly selected adults must be surveyed to…

A: Solution

Q: According to statistics reported on CNbC, a surprising number of motor vehicles are notcovered by…

A: Solution: a. Let X be the number of vehicles were not covered by insurance and n be the sample…

Q: The executives at Sandbachian, inc., having recently solved their widget crisis, have another…

A: Let ‘x’ be the no of defective manhole covers i.e x=40 and n=800 sample propotion (P)=x/n p=40/800…

Q: You work for NASA and are interested in determining the population proportion, with 99% confidence,…

A:

Q: In one​ city, 24​% of adults smoke. In groups of size 140 of​ adults, what is the variance of the…

A: Givenp=0.24n=140x~Binomial(n=140,p=0.24)P(X=x)=(nx)×px×(1-p)n-x      ; x=0,1,2...,n

Q: A physical therapist wants to determine the difference in the proportion of men and women who…

A:

Q: An optometrist wishes to know the proportion of patients who undergo laser eye surgery who end up…

A:

Q: You are running a political campaign and wish to estimate, with 95% confidence, the proportion of…

A: Formula for the sample size needed to estimate a population proportion is

Q: You take a random sample of size 25 students and find the 5 who understand this lecture. With 99%…

A:

Q: A marketing research firm wishes to conduct a poll in a certain region to estimate the proportion of…

A: Solution: From the given information, confidence level is 0.90 and E=0.03.

Q: A university dean of studentswishes to estimate the average number of hours studentsspend doing…

A:

Q: A researcher wishes to estimate the number of households with two cars. How large a sample is needed…

A:

Q: During routine screening, a doctor notices that 20% of her adult patients show higher than normal…

A: Obtain the sample size of a preliminary estimate for p is 0.20 with the 95% confidence. The formula…

Q: In order to estimate the population proportion with a high school education,  you need a minimum…

A:

Q: If the variance of a national accounting examination is 828, how large a sample is needed to…

A: Given data: Variance  = 828 Margin of error = 4 points Confidence level = 99 % To calculate the…

Q: A researcher wishes to estimate the number of households with two computers. How large a sample is…

A: given data   CI = 0.90, P ( - Z< P < Z ) = 0.90 therefore z = 1.645 ( =z table ) E = 6% =…

Q: A polling agency wants to determine the percentage of voters in favour of extending tax cuts. they…

A: Given information- Margin of error, E = 2% = 0.02 Confidence level, c = 95% Since nothing is known…

Q: A Plitical pollster wants to know what proportion of voters think james burger should go away and…

A:

Q: A simple random sample of 28 observations was taken from a large population. The sample mean equaled…

A: It is given that, a simple random sample of 28 observations was taken from a large population with…

Q: From a sample of 500 items, 30 were found to be defective. The point estimate of the population…

A: The point estimate of the population proportion is the sample proportion. The formula for point…

Q: If a manufacturer conducted a survey among randomly selected target market households and wanted to…

A: From the provided information, Margin of error (E) = 6% that is 0.06 Confidence level = 95% The…

Q: A company claims that 90% of its deliveries arrive on time. You take a sample of 74 deliveries, of…

A: Given,   The sample proportion is,

Q: intended population

A: A population is the entire group that you want to draw conclusions about   Intended population:…

Q: A physical therapist wants to determine the difference in the proportion of men and women who…

A: a) Compute the required sample size using the formula: E=zα2 p⏞11-p⏞1n+p⏞21-p⏞2n   Where 'E' is the…

Q: In a sample of 81 elements, the mean was 60 and the variance was 144. What is the standard error for…

A:

Q: You have been hired by a consortium of local car dealers to conduct a survey about the purchases of…

A: Given: Confidence level = 95% Margin of error = 0.03 Formula Used: n = ZαMargin of error2 p(1-p)

Q: A physical therapist wants to determine the difference in the proportion of men and women who…

A:

Q: Suppose you wish to estimate a population mean based on a random sample of n observations, and prior…

A: The population standard deviation is 12.7, the margin of error is 1.6 and probability(or confidence…

Q: A television sports commentator wants to estimate the proportion of citizens who​ "follow…

A: Given Data: Margin of Error=0.22 p=0.54   z-value=1.96

Q: ple of 1000 Americans, it was discovered that 920 of them lived in neighborhoods with acceptable…

A: The point estimate (sample proportion) of the sample of size n can be defined as: p^=xn  Here, x =…

Q: It's believed that as many as 20% of adults over 50 never graduated from high school. We wish to see…

A: Sample size: Sample size is defined as the number of observations in the sample data. The formula…

Q: Based on the Nielsen ratings, the local CBS affiliate claims its 11 p.m. newscast reaches 52% of the…

A: Givensample size(n)=100p^=0.47

Q: A physical therapist wants to determine the difference in the proportion of men and women who…

A: Percentage of level of confidence is 95%. Here, margin of error is, E=0.03.

Q: In terms of skewness, what does it mean if more values are concentrated above the mean? In this…

A: Solution Given more values are concentrated above the mean . So Median will lies right  side to the…

Q: In recent years, approximately 55% of eligible voters take the time to vote in presidential…

A: Givensample size(n)=200x=128α=0.05

Q: A simple random sample of heights of 6400 Englishmen has a mean of 67.85 inches and SD 2.56 inches,…

A: Since the sample size is large so we can assume normality.Null hypothesis: H0: Australians are same…

Q: A survey of 120 fatal accidents showed that in 24 cases the driver at fault was inadequately…

A: Point estimate:   The population parameter which is estimated by using sample statistic is termed as…

Q: In a random sample of 500 teenagers 12 to 17 years old, it was found that 330 have regular access to…

A: A random sample of 500 teenagers 12 to 17 years old; n=500 It was found that 330 have regular access…

Q: rcher asked a random sample of students at the library on a Friday night, “How many hours a week do…

A: If the selected sample or data for analysis is selected in such a way that randomization is not…

Q: If you want to be 99​% confident of estimating the population proportion to within a sampling error…

A: From the provided information, Confidence level = 99% Margin of error (E) = ±0.05 Proportion (p) =…

Q: A researcher uses a repeated-measures design to compare individuals’ performance before treatment…

A:

Q: The manager of a small supermarket chain wants to estimate the proportion of time stockclerks spend…

A: Assume that the population proportion is 0.5. It is known that the critical value for 98% confidence…

Q: The manager of a city recreation center wants to estimate the percent of city residents who favor a…

A: The confidence interval for the population proportion (single sample) is obtained by using the…

Q: A polling company reported that 59% of 1013 surveyed adults said that rising gas prices

A: (a). Find the expected value: The size of the sample taken from the population is n = 1013. It is…

Q: A pollster wishes to estimate the proportion of United States voters who favor capital punishment.…

A: Given that, Critical value: Using the z-table, the critical value at 90% confidence level is

Q: When comparing test scores of two groups, a difference of one point would never be highly…

A: In testing of hypothesis, the sample size doesn’t influence the result of the test.

Q: A physical therapist wants to determine the difference in the proportion of men and women who…

A: Given Error, E=±0.05CL=0.99

Estimation

A new framework of data analysis where the new statistical methods are used for interpreting the results and analyzing the data is known as estimation in statistics.