A statistician computed the Z-scores of all the observations in a sample and after he added all of them the sum was 1.78. He then realized that he had made a mistake in his computation. How did he realize that he had made a mistake?

Q: A random sample of 250 physicians shows that there are 40 of them who make at least $400,000 a year.…

A: We have to find value of test statistics.

Q: An agricultural scientist tests six types of fertilizer, labeled A, B, C, D, E, and F, to determine…

A:

Q: One sample has n = 8 and SS = 168. A second sample has n = 6 and SS = 126. What is the pooled…

A:

Q: For a particular population, a sample of n = 4 scores has a standard error of 6. For the same…

A: Given data,If n=4 then σx =6 If n=16 σx=?

Q: An analysis of variance produces SSbetween=30,SSwithin= 60, and an F-ratio with df= 2,15.. For this…

A: It is given that, SSbetween is 30 and SSwithin is 60.

Q: If all possible random samples of size =44 are selected from a population with 70 and a 8, and the…

A: CEntral limit theorem: For a population with mean μ and a standard deviation σ, the distribution of…

Q: A sample of n = 81 scores is obtained from a population with µ = 80 and σ = 27. If the sample mean…

A: Given that, Sample size, n = 81 Z score = +2.33 μ=80 and σ=27

Q: A random sample of n = 16 scores is obtained from a population with σ = 12. If the sample mean is 6…

A: Consider, Sample size (n) = 16 Standard deviation (σ) = 12 (Sample mean – Population mean) = 6

Q: I have a z statistic of 2.91 from a one tailed test. What is my p value?

A: P(z>2.91 )=? P(z>2.91)= 1 - P(z<2.91) From z table the critical value at 2.91 is 0.9982…

Q: Find the corresponding z-score for a sample of n = 4  and M = 38 taken from a population with a mean…

A: Given,Sample size (n)=4Sample mean (M)=38Population mean(μ) =40Standard deviation (σ)=8

Q: An analysis of variance produces SSbetween = 30, SSwithin = 60, and an F-ratio with df = 2, 15.  For…

A:

Q: An executive believes that a new energy drink his company developed will increase an individual's…

A: Paired t-test statistic results:For testing whether the new energy drink increase an individual’s…

Q: A researcher claims that the incidence of a certain type of cancer is less than 5%. To test his…

A: In this context, a researcher claimed that the proportion of incidence of particular type of cancer…

Q: .The average length of a flight by regional airlines in the United States has been reported s464…

A: We have given that  Sample size n = 30 Sample mean =479.6 Standard deviation =42.8

Q: The claim is that the proportion of accidental deaths of the elderly attribute to residential falls…

A: From the provided information: The hypotheses can be constructed as: Null hypothesis: H0: p = 0.15…

Q: A sample of n = 100 scores is selected from a population with u = 50 and o = 5. If the sample mean…

A: Given Sample Mean: x̄ = 49 Sample Size: n = 100 Population Mean: μ = 50 Population Std Dev: σ =  5…

Q: If my p-value is 0.062 should I reject it and support my claim?

A: Basic: Rejection or acceptance of null hypothesis  is totally depending  on p values and…

Q: Find the t-value for a=0.005 one-tailed test with n=25.

A: Computation of degrees of freedom:It is given that α=0.005; n=25.Also, it is given that the test is…

Q: A sample of n = 4 scores is selected from a population with μ = 50 and σ = 12. If the sample mean is…

A: Given datan = 4μ = 50 and σ = 12, sample mean M= 56z-score is given by

Q: A physician wants to determine if a supplement is effective in helping men lose weight. She takes a…

A: It is given that the sample size (n) is 6 and the hypothesized test is left- tailed. The level of…

Q: Q2 // If you know that the spring class 129.5 and its frequency equals 9 and the cumulative…

A: Given :  The spring class is equal to 129.5  The frequency is equal to 9  The class preceding the…

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 statistician wants to determine if there is a difference in the fuel efficiency of cars between…

A: Given info: The claim of the test is there is a difference in the fuel efficiency of cars between…

Q: A sample of n = 15 scores ranges from a high of X = 11 to a low of X = 3. If these scores are placed…

A: Given: Lowest value of X = 3 Highest value of X = 11

Q: A Social Psychologist is interested in finding out if there is a difference in the anxiety…

A: Hypotheses for the test are given below:

Q: Suppose that the 101 randomly selected eighth-grade students (mentioned in question 6) took a…

A: From the provided information, The test statistic t = -2.32 And p < 0.05

Q: If the data is weight, the z-score for someone who is overweight would be what?? if the data is…

A: Also known as standard score, z-scores are a way to compare two scores that may or may not be from…

Q: A random sample of n = 49 scores is obtained from a population with σ = 14. If the sample mean is…

A: It is given that  n=49 σ = 14 Population mean =μ Sample mean,x=4.5+μ

Q: The technology committee has stated that the average time spent by students per lab visit has…

A: An outlier is a point that is not similar to other points. In the histogram, it is easy to identify…

Q: Two researchers are testing the null hypothesis that a population proportion p is equal to 0.30, and…

A: The given null and alternative hypotheses are: H0:p=0.30H1:p=0.30 The sample proportion for…

Q: population of N = 5 scores has a variance of σ 2 = 24. If the scores were from a sample, what value…

A:

Q: A researcher wants to test the claim that convicted burglars spend an average of 18.7 months in…

A: Here, population standard deviation is not known. Hence, it is appropriate to use one sample t-test.…

Q: A researcher conducts an independent-measures study comparing two treatments and reports the t…

A:

Q: You have a population of 100 engineering students at a certain university and you want to interview…

A: Assume, n be the minimum sample size required. N be the population. p^ be the sample proportion of…

Q: A decade-old study found that the proportion, p, of high school seniors who believed that "getting…

A: The sample proportion is, The null hypothesis is, The alternative hypothesis is, Significance…

Q: A researcher obtains t= 2.25 for a repeated-measures study using a sample ofn=10 participants. Based…

A: It is given that t= 2.25. Df = n- 1 = 10-1 = 9.   For α = 0.05: It is given that α = 0.05, the area…

Q: For a population with μ = 80 and σ = 6,what is the z-score corresponding to X = 68?

A:

Q: A random sample of n = 16 scores is obtained from a population with σ = 12. If the sample mean is 6…

A: Then, the z-score is as follows:

Q: Has the proportion of Americans that are "20-somethings" decreased? According to the US Census…

A: Solution-: Given: x=65,n=500,P0=0.151,α=0.10 We want to determine, (e) p-value=? (f) At α=0.10…

Q: 3. Suppose that the psychologist in the previous question predicted that girls have higher verbal…

A: Note: "Since you have asked multiple question, we will solve the first question for you. If you want…

Q: If there are 4 scores per group and the t value is 2.34, what is the p value for a two-tailed test…

A: Note: Thank you for the question. Since it is given that, there are 4 scores per group we are…

Q: A random sample of n = 9 scores is obtained from a population with µ = 50 and σ = 9. If the sample…

A: Given, Mean = 50 Standard deviation = 9   Sample size = 9 Sample Mean = 53   The objective is to…

Q: A dietician read in a survey that 70.5% of adults in the U.S. do not eat breakfast at least 3 days a…

A: It is need to be tested whether the population proportion of adults in U.S who do not eat breakfast…

Q: For any population, a z-score of -2.00 is a more extreme score than a z-score of +1.00. TRUE OR…

A: Z-score: The z-score determines the relation of the individual values with mean of distribution. The…

Q: If all other values are held constant, what happens to the value of t when sample size increases ?

A: The formula to calculate t value (test statistic) can be written as:

Q: The manager of the Cottonwood Grille recently selected a random sample of 18 customers and kept…

A: E) For the given sample, Mean=38.5, from the excel function, =AVERAGE(K1:K18) standard…

Q: sample of n = 10 score has ss= 108 what is the variance for this sample

A:

Q: One sample has a sample size of n = 8 and SS = 168. A second sample has a sample size of n = 6 and…

A: given: The pooled variance for these two samples is given by

Q: The manufacturer of a new racecar engine claims that the proportion of engine failures due to…

A:

Q: All the possible samples of n = 4 scores are selected from a population with µ = 20. If the average…

A: Given information, All the possible samples of n = 4 scores are selected from a population with µ =…

Confidence Intervals

When we calculate intervals in probability and statistics, it can be simply termed as finding out a confidence interval. The confidence interval is usually calculated from the data set which is observed. The value of the parameter that needs to be calculated is present here only.