what is the role of confounding variables and the best way to design a study to limit confounding variables?

Q: A standardized test has a pop. mean of 152 and a standard deviation of 16. Nicole has a score of…

A: From the provided information, Mean (µ) = 152 Standard deviation (σ) = 16 X~N (152, 16)  Nicole has…

Q: from 1 to 10. The graph below summarizes their choices. The height of the bar above a number…

A:

Q: Identify any errors within the above testing approach and write out the hypothesis test correcting…

A: Given is a question for hypothesis testing for regression coefficient.

Q: Construct a frequency distribution from the following data. a) Use 9 classes to create frequency…

A:

Q: relation to the regression line? The equation of the regression line is �^=140+(−0.0667)�. Where is…

A:

Q: Women in psychology then and now. The following table lists the distribution of degrees in…

A: given frequency distribution

Q: A study was conducted to demonstrate that soybeans inoculated with nitrogen-fixing bacteria yield…

A: Given: There are 8 inoculated plants (I) and 8 uninoculated plants (U). Sample number I U 1…

Q: a) Show that the normal approximation to the binomial can appropriately be used to calculate…

A: Given that, X ~ bin(n = 201, p = 0.45) q = 1-p = 1-0.45 = 0.55 Show that a normal approximation to…

Q: The table below represent the scorer of 40 students in a long quiz. Class Interval Frequency Class…

A: Given that Frequency distribution table Class interval  Frequency  5-9 4 10-14 2 15-19 6…

Q: 15. During a recent period of high unemployment, hundreds of thousands of drivers dropp- their…

A: Given Information:   Yes No Row Total 18 to 34 1500 340 1840 35 and over  1900 260 2160…

Q: Item# 11 | Multiple Choice As used in quality, it refers to those quality characteristics that…

A: Given that  As used in quality, it refers to those quality characteristics that conform to…

Q: DIRECTION: Read each statement carefully. Write T if the statement is TRUE but if it's FALSE, change…

A: 1. FALSE. In gathering data, Direct method is a person-to-person encounter b/w the source of…

Q: Each respondent was given a score, from 1 to 15, on his or her knowledge of the COFLU-20. A score…

A: Given The data is as follows:   Knowledge level   Age group Poor Satisfactory Good Total…

Q: 2. Bernoulli Trials Complete the blanks in the following question with the appropriate answer.…

A: Given data P(Head) =0.40P(Tail) = 0.60P(sequence of HHTH) = ?

Q: Using 5,000 observations, the following histogram summarizes Variable X. 0.5 0.4 Relative 0.3…

A: We have given, Using the 5000 observations, the variable X summarizes histogram. For the histogram…

Q: A population of values has an unknown distribution with = 212.6 and σ = = 55.4. You intend to draw a…

A: Given data  μ = 212.6σ = 55.4n = 160

Q: The following data represents the age of 30 lottery winners. 24457 22 29 33 38 38 45 47 40 49 61…

A: age observation 20-29 22,29 30-39 33,38,38,39 40-49 40,41,44,45,47,48,49 50-59 54,55,56,59…

Q: 11.  B(n=12,p=1/4). a. Find B(3); b. expected value c. standard deviation

A: Given data  X~B(n=12,p=1/4) binomial distribution P(x=X) = nCxpxqn-x

Q: 5. Suppose T≥ 0 is a continuous RV with density f. Recall that for n ≥ 1, the n-moment of T is…

A: From the given information, T≥0 is a continuous random variable with density f. ETn=∫0∞tnftdt

Q: 19. Combinatorics 1 Complete the blanks in the following question with the appropriate answer.…

A: 10 red balls 10 blue balls 10 yellow balls  _______________________ 330 total balls   draw 5 balls…

Q: Item#17 | Multiple Choice he Cp value of 1.33 is desirable, and when Cp = Cpk, the process is: b.…

A: Solution:  Given information: The Cp value  is 1.33

Q: The gestation period (length of pregnancy) of a certain species is approxi- mately normally…

A: Given,mean(μ)=6standard deviation(σ)=12

Q: Define the null and alternative hypothesis for this test in mathematical terms and in words ,report…

A: Given that, Let μ be the population mean diameter of the ball bearing. Sample size (n) = 50…

Q: QUESTION S Identify the population of the following example. In a poll of 50,000 randomly selected…

A: Solution:- (5) Identify the population of the following in a poll of 50,000 randomly selected…

Q: Compare homoscedasticity with heteroscedasticity? Illustrate with suitable diagrams. What are the…

A: Homoscedasticity:The term homoscedasticity refers to the same scatter, which assumes that in a…

Q: Under what circumstances is that fact also true for systematic random​ sampling? Explain your

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Q: A supermarket has been selling discounted apples in bundles of five at their counters. A random…

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Q: (b) Assuming that the distribution of times is mound shaped and approximately symmetric,…

A: Let X be the playing time for a large collection of compact discs. Assuming that the distribution of…

Q: Find the slope of the line shown below -3 -2 slope = 3- 2 -2 -3 T? -5+

A: Given The geometrical figure is given by Let the straight line be AB which intersect the X axis and…

Q: In order to check whether the variation of waiting times is in control, the quality control analyst…

A: The data on waiting time at a food restaurant for four orders are taken for 12 consecutive days. The…

Q: To assess the relationship between monthly sales of a product and monthly advertising…

A: The question is about regression Given : Coefficient of " Advert " ( b1 ) = 1.1762   To find :…

Q: 2. Suppose that the cumulative distribution function of the lifetime of a piece of operating…

A: Given information: Ft=1-e-0.6t-0.6te-0.6t

Q: A sample of 30 UDM Chemistry students from the College of Science were given an IQ test. The sample…

A: For the distribution of students' IQ scores, it is given that: The sample size, n=30 The sample…

Q: A Chinese restaurant offers a Chow Mein dinner with a choice of one of three kinds of rolls (egg,…

A: The information provided in the question are as follows : Number of kinds of rolls = 3 Number of…

Q: Construct a frequency distribution for the given data set using 6 classes. In the table, include the…

A: The question is about frequency distribution Given :   To find : 1 ) Construct freq. table 2 )…

Q: What is the expected value of X

A:

Q: The population mean will always be the same as the mean of all possible X¯ that can be computed from…

A: We have to check if the given statement is true.

Q: Express the confidence interval (54.8% , 69.6 % ) in the form of p + E. % + %

A: The question is about confidence interval Given : CI : ( 54.8 %, 69.6 % ) That means, Lower lim. =…

Q: L: Male and female respondents to a questionnaire on gender differences were categorized into three…

A: Given that: Responses according to gender are displayed using a table (observed frequency):   Set…

Q: Consider that 30% of the students of a given class are engaged in project during the 13th week of…

A: Given that: Probability that a randomly selected student is engaged in a project, PE=0.30…

Q: 9. Which measures aren’t resistant? (more than one could be correct) a. mean b. median c. IQR d.…

A: We have to find which of the given measures are not resistant measure. If a measure is not affected…

Q: Use the figures below to answer the following question. Panel A is most likely showing a Panel A…

A: Two figures corresponding to panel A and Panel B is given.

Q: Calculate the missing values. (Round the final answers to 2 decimal places.) Discount rate (%)…

A: Given that, list price = $ 49.95  and net price = $34.97

Q: Find the 25th, 50th, and 75th percentile from the following list of 32 data 9 14 31 47 3 4 19 32 49…

A: here data is arranged in accending order already. ith percentile = i(n+1)100th observation No. of…

Q: 5. A researcher wanted to know if there is a relationship between level of education, previous…

A: Given that, There are three variables: education level, current salary, and previous experience. The…

Q: If the data given below is assumed to be normally and not normally distributed, answer the following…

A: Respondents No of years playing without training with training with presence of trainer 1 5 8 15…

Q: 3. Using the same data in #2, a. Calculate Spearman's r. b. Which of the two correlation…

A: X = Violent incidents Y = Officers assigned We have to calculate Spearman's r  r = 1 -  6*…

Q: estimate is within 3 of the true population mean. How large of a sample size is required? Round up…

A: Given that, Population standard deviation (σ) = 74.3 Margin of error (E) = 3 Confidence level (C) =…

Q: The following table represents the scores on the Mini-Mental State Examination (MMSE) for patients…

A: Given data: Patient MMSE Score A 22 B 17 C 19 D 22 E 19 F…

Q: 55 randomly selected students were asked the number of pairs of shoes they have. Let X represent the…

A: We have given that Number of pairs of shoes  Frequency  4 3 5 8 6 5 7 6 8 2 9 3 10…