When finding confidence intervals for one population mean, if you want a 95% confidence interval, why must you divide 0.05 by 2? Why do think it is important in data analysis to have an adequate sample size?  What are some issues that could arise if a sample size is to small? Or even too big?

Q: Suppose we have data from a sample. The sample mean is 32, and the error bound for the mean is 2.4…

A: From the provided information, Sample mean (x̅) = 32 Error bound (E) = 2.4 Confidence level = 95%

Q: Find the sample size needed if a 98% confidence interval has a 'margin of error' of 4% if .. a) You…

A: From the provided information, Margin of error (E) = 0.04 Confidence level = 98% The z value at 98%…

Q: If the 95% confidence interval for a population mean from a certain sample is (-6.3, 4.5), then (а)…

A: Given that,95% C.I. for a population mean from a certain sample is (-6.3, 4.5)

Q: If an interval estimate is said to be constructed at the 90% confidence level, the confidence…

A: #If an interval estimate is said to be constructed at the 90% confidence level, then confidence…

Q: 1. When we construct a 90% confidence interval, we say that “we are 90% confident that the true…

A: 1. By this phrase we mean that if we collect a large number of different samples of the same size…

Q: You are given the following formula - partially completed - for a confidence interval: 6±2.326*0.8.…

A: Given Confidence interval is 6±2.326*0.8It is in the form ofx±Zc*(σn)Where x=6Zc=2.326σn=0.8Margin…

Q: If n=360 and ˆpp^ (p-hat) = 0.6, construct a 90% Confidence Interval. In order to use technology,…

A: Since the question emphasize to use technology. I will use excel to solve this question. Note: Press…

Q: (e) Explain why you might want to potentially use the formula n > 4h? instead of n 2 2P (1 – p) when…

A: when there is no prior estimate of the sample proportion () is known, then we use, putting the…

Q: You have recently had a debate with a friend about who uses smartphones the most. Your friend…

A:

Q: An epidemiologist is worried about the prevalence of the flu in East Vancouver and the potential…

A: If both the expected number of success and expected number of failures are greater or equal to 10,…

Q: An epidemiologist is worried about the prevalence of the flu in East Vancouver and the potential…

A: Given data isn=332x=36p^=xn=36332=0.108434Margin og error(E)=0.04Confidence level=95%

Q: If, based on a sample size of 850​, a political candidate finds that 479 people would vote for him…

A: Given that  n=850 , X=479 Find 95​% confidence interval for his expected proportion of the​ vote?

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

A: Solution: a. From the given information, confidence level is 0.96, p=0.48 and E=0.03.

Q: margin of error for a 95% confidence interval is approximately 2 times the standard error.  True…

A: The standard error can be calculated as: SE=σnorSE=sn Here, σ  or s = Standard deviation n = Sample…

Q: You plan to conduct a survey to find out the proportion of students who enjoy taking classes…

A: Given  The margin of error is given as m=0.02 At a 90% confidence interval, α=0.1 As the proportion…

Q: n a survey, the planning value for the population proportion is p*=.25 . How large a sample should…

A:

Q: READ THE FOLLOWING PROBLEM AND ANSWER WHAT IS ASKED. SHOW YOUR SOLUTION. The average weight of 25…

A: 1. Let, X be the weight. Given, Sample mean= x¯ =400 Sample size =n =25 Sample sd = s =20 For 95%…

Q: using the confidence interval method, to test that population mean equals 14, a researcher obtains…

A: Solution: State the hypotheses. Null hypothesis: H0: µ=14. That is, the population mean is equal to…

Q: If n = 390 and p^ (p-hat) = 0.8, construct a 99% Confidence Interval.

A: Given that, Sample size n=390,   and proportion of successes in sample of size n=0.8 (1-α) %…

Q: What are the two major areas of statistical inference? Discuss their importance. b. Is the 95%…

A: Statistical inference helps to infer the properties of the population from a given sample of data.…

Q: What Influences the Sample Size? We examine the effect of different inputs on determining the sample…

A:

Q: A sample of 700 from population A has a proportion of interest of 0.24 while a sample of 600 from…

A: Confidence Interval: The form of the confidence interval is, CI = Point estimate ± Margin of error…

Q: In order to make the decision for one business, your team constructed a 90% confidence interval, the…

A: For 90% confidence interval, the width of that confidence interval is 500.We have to reduce the…

Q: 1. In a recent study, the researchers want to find the information about the percentage of adults…

A: Given datan = 3026proportion of people who prefer to get their news online = 0.38

Q: If n=360 and p (p-hat) = 0.2, construct a 98% Confidence Interval. In order to use technology, you…

A:

Q: An epidemiologist is worried about the prevalence of the flu in East Vancouver and the potential…

A:

Q: (a) If researchers decide on a 4.2% margin of error for a 95% confidence interval. What sample size…

A: From provided information, Sample proportion is (p̂) = 50% i.e. 0.5 The sample size can be…

Q: In the Laboratory Activity, we used 90% confidence interval instead of 100%, why is this so? Why not…

A: Confidence Interval A confidence interval (CI) is a set of numbers that assess the validity of the…

Q: How do I input the following into Excel? You plan to conduct a survey to find what proportion of…

A: The confidence level is 95%. The margin of error is 0.02 Since the proportion is not known, p= 5/50…

Q: Suppose that a friend of yours says that they were reading about confidence intervals and ask you…

A: Here's, x-bar and mu, first of all x-bar is the sample mean and mu is the population mean. We use…

Q: A 95% confidence interval is narrower than a 90% confidence interval for the same data set. O True O…

A: We have to find given probability.

Q: You want to survey students to see what proportion of them have taken Statistics 101. This survey…

A: Margin of error(M) = 4% = 0.04 Confidence interval = 95%

Q: Briefly describe the relationship between confidence interval and hypothesis testing.

A: Briefly describe the relationship between confidence interval and hypothesis testing.   A 95% CI…

Q: The concept of a confidence interval for a population proportion is similar, but the math is a…

A: We have given thatn = 240x = 48

Q: The relationship between sample size and the width of a confidence interval may be explained by the…

A: The relationship between sample size and the width of a confidence interval may be explained by the…

Q: A soft drink company surveys 500 shoppers and finds that 61% of shoppers prefer diet soda to regular…

A:

Q: If n=110 and ˆpp^ (p-hat) = 0.8, construct a 95% Confidence Interval.In order to use technology, you…

A: Given:

Q: You report a 90% confidence interval for the mean based on a sample. If you repeated your sampling…

A: The confidence interval at 100 (1 – α) % confidence level gives us an interval estimate about the…

Q: Here are summary statistics for randomly selected weights of newborn​ girls: n=165​, x=33.6 ​hg,…

A: From the provided information, Sample size (n) = 165 Sample mean (x̅) = 33.6 Sample standard…

Q: Some of the following questions might be more challenging, but we want you to wrestle through them…

A: Obtain the value of the point estimate. The value of the point estimate is obtained below as…

Q: two 95 percent confidence intervals will be constructed to estimate the difference in means of two…

A: Solution: The confidence interval for the difference in means calculated by using the formula:

Q: When we construct a confidence interval estimate of the difference between population proportions…

A: We know that confidence intervalC.I. is given by C.I.=x¯±z×σn…

Q: A confidence interval has been determined  to be -6<u<6, what was the sample mean that was used to…

A: Confidence Interval: Confidence interval is the interval estimate of the population parameter. It is…

Q: how many samples out of 100 would you expect to not include the true population mean within their…

A: here given ,  confidence level =  90%  sample size  = 100

Q: Siblings Mary and David are each attempting to estimate the proportion of families in their…

A: Mary confidence intervalgiven that,size(n)=50success rate ( p )= x/n = 0.1level of significance, α =…

Q: Which is true about a 95% confidence interval for a population proportion based on a given sample? A…

A: The given information about the 95% confidence interval for a population proportion.

Q: Suppose you perform a similar survey at CAS, Nizwa with 35 randomly selected students; the sample…

A: Given data, n=35 x=5.1 s=2.6 df=n-1=34 α=0.05t-critical value is tc=2.032

Q: How large a sample should she take to achieve this? Please carry answers to at least six decimal…

A: Given: sample size, n=332 number of people have flu, x=36 Margin of error, E=0.03 confidence…

Q: Consider the one-sided confidence interval expressions for the mean of a normal population. Round…

A: Givena)Confidence interval = 80%

Q: The following questions are concerned with confidence interval estimation of one population mean.…

A: We need to identify if the given statements are true