A researcher is looking at data from a large population with a standard deviation that is much too large. In order to concentrate the information, the researcher decides to repeatedly sample the data and use the distribution of the means of the samples? The first effort used sample sized of 100. But the standard deviation was about double the value the researcher wanted. What is the smallest size samples the researcher can use to remedy the problem?

Q: How do you do the following problem: If we know that the population mean of the scores for the SAT…

A:

Q: 12. The red blood cell count for a population of adult males can be approximated by a normal…

A: We have given that  X~N( μ , ?^2 )    μ = 5.4    , ? = 0.4   Z-score =( x - μ )/?  ,

Q: The variance of stock A is 0.0066 and the return is 0.115 ,  while B has the same return but 0.2 as…

A: Measure of central tendency measures the central or average value of a dataset. Measured of…

Q: An economist wants to estimate the mean per capita income (in thousands of dollars) for a major city…

A: Given information:Mean income(μ) = $22.2 (in thousands of dollars)Variance (σ 2)= $136.89Standard…

Q: An economist wants to estimate the mean per capita income (in thousands of dollars) for a major city…

A: The population mean per capita income for a major city in State C is .It is needed to find the…

Q: An IQ test is designed so that the mean is 100 and the standard deviation is 16 for the population…

A:

Q: A researcher want to determine an interval estimate for the average weight of adult gorillas in…

A: Given confidence level=99%Margin of error(E)=8.3standard deviation(σ)=15.2

Q: Suppose someone was diagnosed with a form of cancer that had a median survival time of eight months.…

A: Introduction: The median of a data set is a value that divides the top half (or top 50%) of the data…

Q: a sociologist studies two towns A and B. Town A has a mean income of x=70,000 with standard…

A:

Q: The director of research and development testing and new drugs she wants to know if there's evidence…

A: Test statistic:Denote μ as the claimed mean; μ = 384. In a random sample of n = 79, the sample mean…

Q: Suppose you were given a data set, and you want to determine whether the distribution from which the…

A: A normal dist. is symmetric and has a bell-shaped curve.

Q: If you chose to compute a mean for a variable, which measure of variability would you most likely…

A:

Q: An IQ test is designed so that the mean is 100 and the standard deviation is 17 for the population…

A: For the distribution of IQ scores for normal adults at the population level, it is given that:…

Q: A researcher want to determine an interval estimate for the average weight of adult gorillas in…

A: From the provided information, Confidence level = 90% Margin of error (E) = 3.1 Standard deviation…

Q: The distribution number of fingers is unimodal and left skewed. Which of the following is true? The…

A: Given that the distribution number of fingers is unimodal and left skewed.

Q: Answer all the questions. Determine if the following statements are TRUE or FALSE. If False, write…

A: Normal distribution is a continuous distribution which has many real life applications. Normal curve…

Q: I am trying to determine the variance, standard deviation and the CV for a set of data. The data…

A: Descriptive statistics are referred to as the summary statistics.

Q: You used SS = (x-x)² when calculating variance and standard deviation An alternative formula for the…

A: Given sample data are,15, 14, 17, 22, 17, 19, 18, 19, 16, 14, 20, 15, 18, 17, 17, 18, 19, 18, 19,…

Q: facing a shortage the student activity council decides to reduce funding for each of it's student…

A: Given : facing a shortage the student activity council decides to reduce funding for each of it's…

Q: One of the z-score formulas will help on this question. Scores on the SAT test are normally…

A: Given X ~ N (500, 100) P(Z<x -μσ) = PZ<700-50010                     = P(Z<20)…

Q: See photo ) The data set on the left represents the annual rate of return (in percent) of eight…

A:

Q: What is the mean absolute deviation of 1, 5, 8, & 10? Show your solution

A:

Q: What is the minimum sample size necessary to estimate the population mean? Round your answer up to…

A: Given that, Confidence level (C)=99%=0.99α=1-C=1-0.99=0.011-α2=1-0.012=0.995Margin of error…

Q: Solve this for me

A: The objective of this question is to calculate the z-scores for the lengths of two sharks, Arturo…

Q: is the variance of distribution?

A: It is given that the probability distribution of X in the solution of the problem. Also we have Mean…

Q: Q.Discuss coefficient of mean deviation

A: Coefficient of mean deviation is defined as deviation of data values from mean.

Q: If you measure a quantity four times, and the standard deviation of the mean is 1.0 % of the average…

A: The goal of this problem is to check whether the confidence interval for the true value is within…

Q: Why is it useful to know the standard error of the mean? (Choose all that are correct.) It is…

A: here we know that Standard error is the standard deviation of its sampling distribution. or an…

Q: The sum of deviation scores in any distribution (population or sample) is always equal to 0.…

A: Let us take an example.   Let X be random variable    we know that Meanx¯=∑xn Therefore, ∑x=nx¯

Q: uppose you have the population value 50 and 80 and that their corresponding z-scores respectively.…

A: Given Data: Population value=50 and 80   we also know the corresponding z-score

Q: For the following sample of n = 6 scores: 0, 11, 5, 10, 5, 5

A: The sample and population variation is given as s2=∑i(xi-x)2n-1σ2=∑i(xi-μ)2N Population mean is…

Q: A population is normally distributed with a mean of 20.  What is the population standard deviation…

A:

Q: An economist wants to estimate the mean per capita income (in thousands of dollars) for a major city…

A:

Q: Scenario 3: On an examination given to students at a large number of different schools, the mean…

A: Formula

Q: If a researcher wants to determine if one sample mean significantly differs from a population mean…

A: The given claim is one sample mean significantly differs from a population mean. The population mean…

Q: If your score on your next statistics test is converted to a z score, which of these z scores would…

A: Solution

Q: 4. How do you interpret a z - score? 5. How to calculate a raw score when a z- score is known?

A: Introduction: For a random variable, X with mean m, and standard deviation s, the z-score…