Let X be the random variable with the following distribution: x: -2 3 5 P(X=x): 0.3 0.2 0.5 Find the variance of X (four decimal places)
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Let X be the random variable with the following distribution:
x: -2 3 5
P(X=x): 0.3 0.2 0.5
Find the variance of X
(four decimal places)
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- Random Variable Name: Section:, I. Classify the following random variables as discrete or continuous. 1. X= the number of mobile phones sold in one week in the AB store 2. Y= the weights in pounds of newly born babies in a hospital nursery 3. X the number of cars in a parking lot every noon 4. Y= the number of gifts received by a birthday celebrator 5. X= the length of time spent playing video games in minutes 6. Y= the number of students enrolled in Grade 11 in your school 7. X=the number of points scored in a basketball game 8. Y= the number of employees in a call center who are Bachelor of Science in Nursing graduates 9. X=the heights of 10. Y= the amount of money spent by a family in one month in your school in meters Answers: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.If Y is Normally distributed , and p(y < 170 ) = 0.14 p ( y > 200 ) = 0.03 then the values of the mean and variance of Y , respectively areLet x be a random variable that represents red blood cell count (RBC) in millions of cells per cubic millimeter of whole blood. Then x has a distribution that is approximately normal. For the population of healthy female adults, suppose the mean of the x distribution is about 4.78. Suppose that a female patient has taken six laboratory blood tests over the past several months and that the RBC count data sent to the patient's doctor are as follows. 4.9 4.2 4.5 4.1 4.4 4.3 (i) Use a calculator with sample mean and standard deviation keys to find x and s. (Round your answers to two decimal places.) x = s = (ii) Do the given data indicate that the population mean RBC count for this patient is lower than 4.78? Use ? = 0.05. (a) What is the level of significance?State the null and alternate hypotheses. H0: ? < 4.78; H1: ? = 4.78H0: ? = 4.78; H1: ? ≠ 4.78 H0: ? = 4.78; H1: ? < 4.78H0: ? = 4.78; H1: ? > 4.78H0: ? > 4.78; H1: ? = 4.78 (b) What sampling…
- Consider the following probability distribution function of X and Y: 1 2 0.35 0.05 Y 1 0.15 0.45 Find the variance of X and the variance of Y.Which of the following is a true statement? A. The expected value is the most frequently occurring value of the random variable. B. Variance is always >=0 C. Variance can be negative D. F(x)=P(X=x)Let x be a random variable that represents red blood cell count (RBC) in millions of cells per cubic millimeter of whole blood. Then x has a distribution that is approximately normal. For the population of healthy female adults, suppose the mean of the x distribution is about 4.64. Suppose that a female patient has taken six laboratory blood tests over the past several months and that the RBC count data sent to the patient's doctor are as follows. 4.9 4.2 4.5 4.1 4.4 4.3 (1) Use a calculator with sample mean and standard deviation keys to find x and s. (Round your answers to two decimal places.) x=| S= (ii) Do the given data indicate that the population mean RBC count for this patient is lower than 4.64? Use a = 0.05. (a) What is the level of significance? State the null and alternate hypotheses. Ο Hg: μ= 4.64; H1: μ 4.64 Ο Ηρ: μ> 4.64; H1: μ = 4.64 Ho: u = 4.64; H1: u * 4.64 (b) What sampling distribution will you use? Explain the rationale for your choice of sampling distribution. O…
- Let xbe a binomial random variable with a variance of 0.48, q 0.6 and n=2. Find E(2x-3) 2.4 -1.4 O None O 1.4Consider the following data: 7 8 P(X = x) 0.2 0.2 0.2 0.2 0.2 %3D Step 2 of 5: Find the variance. Round your answer to one decimal place. 5.Let X be the random variable with the following distribution: x: -2 3 5 P(X=x): 0.3 0.2 0.5 Find the mean four decimal places
- s t n 16. The following are some of the particulars of the distribution of weight of boys and girls in a class : Girls Boys 100 50 Number Mean weight 60 kg 45 kg 4 Variance (a) Find the standard deviation of the combined data (b) Which of the two distributions is more variable ? (b), tn, o AL.The 2021 World Happiness Report shows that the mean World Happiness Index is 5.533 with a variance of 1.146. Assume that the data are normally distributed, what will be the index of +1σ? 6.679 6.630 6.603 None of the AboveThe discrete random variable X has the probability distribution given by: -1 1 3 P(X=x) 0.2 0.4r 0.2 a. Determine the following probability: P(X=1) = ? Answer in exact fraction or exact decimals b. What is the expected value of the random variable X? c. What is the variance of the random variable X? Answer in exact fraction or exact decimals d. Find the variance of the random variable Y, where Y = 6 – 2X Answer in exact fraction or exact decimals