Two random samples are selected from two independent populations. A summary of the samples sizes and sample means is given below:   ?1=45,?2=50,?¯1=57.4?¯2=73n1=45,x¯1=57.4n2=50,x¯2=73   If the 92.5% confidence interval for the difference ?1−?2μ1−μ2 of the means is (-18.6761, -12.5239), what is the value of the pooled variance estimator? (You may assume equal population variances.) Pooled Variance Estimator =

Q: A 99% confidence interval for is given by (0.89, 2.34). Based on this interval what can be said…

A: 95% CI for difference between σ2  = (0.89 , 2.36)

Q: Bob selects independent random samples from two populations and obtains the values p1 = 0.700 and p2…

A:

Q: [t (47) = -8.21, p = .03] Based on the parenthetical statement given above, what is the sample size…

A: The t-critical value at 47 degrees of freedom is -0.82.

Q: Construct the indicated confidence interval for the difference between the two population means.…

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Q: Find a 94% confidence interval for A given that x = 20. a = 3. n = 30

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Q: A survey of 500 randomly selected students was taken and 200 responded that they favor candidate Z…

A: The confidence interval given is (-0.3090, -0.1767)This interval represents the range within which…

Q: Give a 99.8% confidence interval, for μ1−μ2 given the following information. n1=20 ¯x1=2.91,…

A:

Q: ind the 95% confidence interval for μ given that n = 16, X̄ = 28 and σ = 6.

A: Given Information: Sample size n=16 Sample mean x¯=28 Population standard deviation σ=6 Confidence…

Q: Given two independent random samples with the following results: n1=13x‾1=149s1=27n1=13x‾1=149s1=27…

A: 90% confidence interval means, we are 90% confident that the population means lies between some…

Q: A random sample of size n = 40 is drawn from a population with the 9) ( (unknow population mean µ.…

A:

Q: Two random samples are selected from two independent populations. A summary of the samples sizes and…

A: From the provided information,

Q: Given a critical t score of -2.33 and t observed being -2.01, the decision you should make is…

A: It is given that the critical t score is -2.33 and the observed t value is -2.01.

Q: If n = 108, ¯xx¯ = 29 and σσ = 2.6, construct a 91% confidence interval. Give your answers to three…

A: Given Data: x¯=29σ=2.6n=108   z-value corresponding to 91% confidence level=1.695

Q: A sample of n = 4 scores is selected from a population with an unknown mean. The sample has a mean…

A: This simple confidence interval uses a t statistic and sample mean (M) to generate an interval…

Q: size n=36 is taken from a normally distributed original population. The sample standard deviation is…

A: The variance is: s2 =72 4949

Q: Construct a 95% confidence interval for ₁-₂. Two samples are randomly selected from each population.…

A: giiven data n1 = 50n2 = 60x¯1 = 25x¯2 = 23σ1 = 1.5σ2 = 1.995% ci for μ1-μ2.

Q: = 03 = 10. For each group, population standard deviations are known as o1 we observe 50 samples, and…

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Q: Only about 16% of all people can wiggle their ears. Is this percent lower for millionaires? Of the…

A: Given information- Population proportion, p = 0.16 Sample size, n = 357 Significance level, α = 0.01…

Q: Bob selects independent random samples from two populations and obtains the values p1 = 0.700 and p2…

A:

Q: A biologist hypothesizes that the mean life expectancy of a mosquito is 14 days. Researchers believe…

A: In this context, the null hypothesis (H0) is that the mean life expectancy (µ) of the mosquitoes is…

Q: The 87.19% confidence interval estimate for p was (0.2, 0.38). Find p′ and ME. pp′=  ME=

A: Given87.19% confidence interval estimate for p was (0.2 , 0.38)

Q: A sample of n=24 is selected from a population = 120 and σ = 40.  If the sample mean is 130, what is…

A: It is given that the population mean, μ=120 and standard deviation, σ=40. For the sample size of 24,…

Q: A sample of n -9 scores is obtained from a population with u- 70 and o - 18. If the sample mean is M…

A: Given that, n=9μ=70σ=18M=76

Q: The results of a study that used an independent samples t-test was t(28) = 2.14, p = .01. Based on…

A: t(28) means that degree of freedom  = 28 Now, degree of freedom for a t-test one sample case  = n-1.

Q: Assume that you have a sample of n, = 7, with the sample mean X, = 48, and a sample standard…

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Q: Independent random samples of ?=15n=15 observations each are drawn from normal populations. The…

A: We have given that  Independent random samples of n=15 observations each are drawn from normal…

Q: A random sample of n1n1 = 272 people who live in a city were selected and 74 identified as a "dog…

A:

Q: a sample of n=16 scores has mean of M=58 with SS=540. Use the sample to construct the 95% confidence…

A: Solution: From the given information, n=16, M=58 and SS=540.

Q: A 95% confidence interval for the variance of a normal data of size 10 was obtained as [3.5, 24.3]…

A:

Q: A company manufactures printers and fax machines at plants located in Atlanta, Dallas, and Seattle.…

A: Use EXCEL to obtain the ANOVA table.   Follow the instruction to obtain the values for table in…

Q: Given two independent random samples with the following results: n1=7x‾1=129s1=20…

A: The random variable X follows normal distribution. There are two independent samples. Both samples…

Q: A sample of n = 10 scores has a mean of M = 3. What is ΣX for this sample?

A: Solution: From the given information, M=3 and n=10.

Q: Give a 99% confidence interval, for μ1−μ2 given the following information. n1=45, ¯x1=2.76, s1=0.73…

A: 99% CI = (-0.18 , 0.64)    ===================

Q: For a population of normally distributed scores, μ = 155 and σ = 12, approximately what would be the…

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Q: A sample of n = 7 scores is selected from a population with an unknown mean (µ). The sample has a…

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

Q: Scored obtained by a large group of students taking a test are known to be normally distributed. A…

A: Here given that n= 25  So mean, X bar = summation Xi /n = 1508/25 = 60.32 Standard deviation, sigma…

Q: Given two independent random samples with the following results: n1=8x‾1=177s1=29  n2=8x‾2=150s2=14…

A: We have given that,  n1=8x‾1=177s1=29  n2=8x‾2=150s2=14 Then  We will find the 90% confidence…

Q: An Independent sample from two different populations yields the following data. x̄1= 947,x̄2 =…

A:

Q: The scores of a certain population on the Wechsler Intelligence Scale for Children (WISC) are…

A: Since we know population standard deviation, use z-distribution to find z-critical value. Find…

Q: We wish to give a 90% confidence interval for ? .  Here,   denotes the mean value of a normally…

A: given that,sample data: (8 , 12 , 14 , 16 , 20 )sample mean, x =14standard deviation, s =4.472sample…

Q: Given two independent random samples with the following results: ni = 8 x1 = 98 s1 = 11 n2 = 12 X2 =…

A: Given : x̄1 = 98 x̄2 = 121

Q: Give a 99.5% confidence interval, for μ₁ −μ₂ given the following information. n₁ = 20, x₁ = 2.51, s₁…

A: Given: n1 = 20 X1 = 2.51 s1 = 0.68 n2 = 45 X2 = 2.07 s2 = 0.51 Formula Used: Confidence Interval =…