Random variable X has mean μX = 24 and standard deviation σX = 6.   Random variable Y has mean μY = 14 and standard deviation σY = 4.   A new random variable Z was formed, where Z = X + Y.  What can we conclude about X, Y, and Z with certainty?  That is, which one is true? Select one: a. μZ = 38            σZ = 7.211                   X and Y are independent b. μZ = 38            σZ = unknown             X and Y are independent c. μZ = 38            σZ = 6                          X and Y are related d. μZ = 38            σZ = 10                        X and Y are mutually exclusive

An urn contains 7 black and 18 white balls. A ball is randomly drawn from the urn. Let X = 1 if a white ball is drawn and let X = -1 if a black ball is drawn. Find the following a) mean of X b) variance of X Please provide your working and round your answers to 2 decimal places

A population has a mean of 200 and a standard deviation of 50. Suppose a sample of size 100 is selected and x is used to estimate u. (Round your answers to four decimal places.) (a) What is the probability that the sample mean will be within +5 of the population mean? (b) What is the probability that the sample mean will be within +10 of the population mean?

200 poodles 61 are left-paued left -pawed. a random sample of In a random sample ef 220 labradores 38 are Can we conclude that the difference in The tuo sample proportions of left pawed dogs is statistically significont for x= 0.05 ?

level of blood glucose and diabetes are closoly related. Let x bo a random variable measured in milligrams of glucose per deciliter of od. After a 12-hour fast, th random variable x will have a distribution that is approximately normal with mean - 85 and standard deviation 5. What is the probability that for an adult after a 12-hour fast. s less than 7o, b. x is greater than 120?

We have a random variable X1 for population 1 with a mean value of 52 and standard deviation of 3. we have a random variable X2 for population 2 with a mean value of 50 and population standard deviation of 4. we obtain a random sample of 625 elements independently for both populations. what is the probability that the difference in the sample averages X1-X2 is at least 2.3?

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Suppose X, Y, and Z are three independent normal random variables. X has an expected value of 7 and a standard deviation of 2; Y has an expected value of -2 and a standard deviation of 4; Z has an expected value of 5 and a standard deviation of 12. Let T = 3X + 12Y - 2Z Variable X Y Mean(Expected Value) 7 -2 Standard Deviation 2 4 12 Coefficient 3 12 -2 a) What is the expected value of T? b) What is the variance of Z? c) What is the variance of T? d) What is the standard deviation of T? N LO

Total blood volume (in mi) per body wight (in ke) is important in medical research. For healthy aduks, the red blood cell volume mean is about p = 28 ml/kg.t Red blood cell vokume that is too lom ar too high can indicate a medical problem. Suppose that koger has had seven blood tests, and the red blood cell volumes weré as follows Let x be a random variable that represents Roger's red blood cll volume. Assume that x has a narmal distributian and - 4.75. Do the data indicate that koger's red blood cell valume is different (either way) from a- 28 mi/kg? Use a 0.01 lervel of significance. a What is the leval of sigaicance State the null and alternate hypotheses. Will you use a left-lailed, right-laded, or two-tailed test? O H: - 28 ml/kg; H: 2s m/kg; Ima-tailed o Ho: - 28 ml/ka; H 28 m/ka, let-tailed O Ho: 28 mil/kg: H1:- 28 ml/kg; tmo-tailed O Ho: 28 m/ka, H > 28 m/kg; right-laiked (b) What sampling distribution wil you use? Explain the rationale for your choice of sampling distributian.…