What formula is used to gain information about a sample mean when the variable is normally distributed or when the sample size is 30 or more?

Q: This is a Statistics problem.  Is the sample mean from the Poisson distribution normally…

A: A Poisson distribution is the probability of the number of events that occur in a given interval…

Q: Prove the general formula for interval estimation of ratio of population variance.

A: Statement:-  If x1,x2..... xn ~ N(μx, σx2) and y1, y2 .....ym ~ N(μy , σy2) are independent random…

Q: Explain the significance of the mean, variance, and standard deviation for a random variable. Do the…

A: Significance of mean, standard deviation and variance is – Mean: it implies average and the sum of…

Q: How are the standard deviation and variance related to each other?

A: Hi! Thank you for posting the question. Since you have posted multiple questions, we are answering…

Q: The weights of 10-pound bags of potatoes packaged by Idaho Farms Inc. are uniformly distributed…

A: Given : The weights of 10-pound bags of potatoes packaged by Idaho Farms Inc. are uniformly…

Q: The average verbal SAT score for the entire class of entering freshmen is 530. However, if you…

A: given  The average verbal SAT score for the entire class of entering freshmen is 530. However, if…

Q: The average height of women in the freshman clas at UA has historically been 5'4" with a standard…

A: Consider a random variable X, that defines the height of women in the freshman class at the UA.

Q: If 80% of the applicants are able to pass driver’s proficiency road test, find the mean, variance,…

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Q: What happens to the proportion of intervals that include the population proportion as the sample…

A: The formula for the confidence interval of population proportion can be written as: Here n is the…

Q: What are requirements for testing a claim about a population mean with a known?

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Q: How do you find the standard error estimate of two disjoint populations, assuming they have the same…

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Q: Suppose that you draw a random sample from a population where you know the population mean is 36 and…

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Q: What happens to the standard error of an estimate when the sample size in a SRS decreases?

A: Standard error: Standard error is a measure which explains how accurate are the sample means to…

Q: How do I interpret the 6 charcteristics of data when I am only given the mean, median, mode, and…

A: According to the provided information, mean, median, mode, and standard deviation are given.

Q: If the size of a sample is 64 and standard error of mean is 1.5.What should be the sample if…

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Q: What is formula for variance for sample?

A: Variance measures absolute variability in a data set, calculated with respect to the mean. That is,…

Q: What distribution is used in this chapter to make inferences for two population standard deviations?

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Q: Suppose that the national mean weight for a three-year-old girl is 35 pounds with a SD of 3 pounds.…

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Q: As the sample size increases, the variability among the sample means increases decreases remains the…

A: Concept: Variability in a data represent how dispersed data is from its mean.

Q: A researcher wants to calculate the prevalence of Alzheimer’s among members of a specific community…

A: Solution: Given information: Margin of error = E= 0.01 Population proportion = p = 0.1073 Confidence…

Q: If the variance of a Bar examination is 900, how large a sample is needed to estimate the true mean…

A: Variance=σ2=900, margin of error=moe=5, level of significance=0.01

Q: Do I have to take many samples from my population to create a sampling distribution of the mean in…

A: Basics of sampling distribution of mean:The sampling distribution of the sample mean is essentially…

Q: A sample of 46 observations gave sample mean 20 and coefficient of variation 0.6 Then the sample…

A: Given  n=46, Xbar=20, CV=0.6

Q: a sample of 60 grade 9 student age was obtained to estimate the mean age of all grade 9 students. x…

A: A sample of 60 Grade 9 students' ages was obtained to estimate the mean age of all Grade 9 students.…

Q: please explain how to use the standard deviation from the 1-Var Stats statistical output to obtain…

A: Hint:  Standard devation =Variance

Q: Suppose 35% of students intend to major in the health sciences. What is the minimum sample size…

A: Consider that p is proportion of all students intend to major in the health sciences.

Q: Should be consider this score unusual? What is the value of the test statistic?

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Q: What are the steps for a hypothesis test for population mean when the variance is known?

A: Given the variance for hypothesis test for population , To write the steps for the hypothesis test…

Q: A mean is known as a statistic if it is computed from the: Opopulation. parameter. sample.

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Q: Explain kurtosis of the distribution?

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Q: What does it mean that the variance (computed by dividing by N) is a biased statistic?

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Q: The standard deviation of a sample of 100 observations equals 64. The variance of the variance…

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Q: The distribution of sample means will always be normal if taken from a normal population. True or…

A: We know that if population is normally distributed then the distribution of sample means will always…

Q: me in male firefighters and you’ve decided to use the sample mean, ?̅, as the estimator. Explain why…

A: The sample mean refers to a statistic obtained by computing the arithmetic average of the values of…

Q: What proportion of the distribution of sample means is between a z  of 1.34 and z of -1.00?

A: P(1.34<z<-1.00)=?

Q: We have to compare the result of all variables using range,interquatile range,variance and standard…

A: As asked, for the given data we have to compare the result of all variables using the range,…

Q: What is the variance of a data set with mean score of 87.5 and a standard deviation of 2?

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Q: Find out mean deviation from mean by applying direct method from the following distribution: Values:…

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Q: If we could not measure the population mean, we could use the sample mean as a point estimator of…

A: Given:  we could not measure the population mean, we could use the sample mean as a point estimator…

Q: It is important to have a random sample to prevent data manipulation. O True False

A: This question can be solved by applying the concepts of random sampling.

Q: A traffic officer suspects that the mean number of car accidents every week is 4. A sample of 16…

A: Given,  n = 16 μ = 4x¯ = 7σ = 4α = 0.05

Q: What variable is not needed to calculate the sample size for a known population standard deviation?

A: The sample size formula is:

Q: the homogeneity of variances assumption states that the variance in the two samples must be equal?…

A: Homogeneity of variances always make about the population variance not about sample.

Q: A critical part of inferential statistics involves determining how far sample statistics are likely…

A: Inferential statistics have two main uses: making estimates about populations (for example, the…

Q: What is the value of n (the number of observations)? What is the value of Se (standard error for the…

A: In the above output of regression y is starting salary and x is student GPA  From the summary output…

Q: When I’m trying to infer the population mean from a small sample, why do I have to rely on the…

A: Assumptions to use standard normal distribution to estimate population mean:The required conditions…

Q: An excess of high values for the cases distributed on a graph results in a positive skew in the…

A: Skewness :  It is a measure of the symmetry of a distribution. The highest point of a distribution…

Q: Explain in brief about Weibull distribution.

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