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- Let X be the Random Variable representing the number of boys infamilies with 3 children. Find the mean.A national freight delivery service is considering introducing a same-day delivery service at no extra cost. It randomly selected customers in its business areas and recorded the customer satisfaction scores. The score range is between 1-100, where 100 is the highest customer satisfaction. Define X1 as the satisfaction score with ordinary deliveries and X2 as the satisfaction score for the same customers with same day deliveries. Some summary statistics are given as The sample mean of X1 is The sample variance of X1 is The sample mean of X2 is The sample variance of X2 is The sample covariance between X1 and X2 is The sample size is 44.20 142.75 53.86 103.39 81.43 56 If you were to carry out a test to investigate whether outsourcing may improve customer satisfaction, what would your sample size be?Fourty percent of the students in a class of 120 are planning to go to graduate school Find the variance of the binomial distribution.
- A least squares line is given by = 3 + (-2)*x. You are told that the sample variance of x is 25 and sample variance of y is 144. What is the value of the correlation coefficient r?A researcher takes sample temperatures in Fahrenheit of 18 days from Pittsburgh and 16 days from Cleveland. Use the sample data shown in the table. Test the claim that the mean temperature in Pittsburgh greater than the mean temperature in Cleveland. Use a significance level of a = 0.01. Assume the populations are approximately normally distributed with unequal variances. Note that list 1 is longer than list 2, so these are 2 independent samples, not matched pairs. Pittsburgh Cleveland 99 82.1 91.2 60.4 88.1 75.5 91.8 79.5 96 73.3 90.6 57.5 91.5 63.4 69.5 64.1 88.6 78.9 89.2 93 86.2 76.7 83.9 57.5 107.1 58.4 98.5 80.7 82.2 81.4 72.4 55.2 85.2 105.3 The Null Hypotheses is: Ho: µ1 - µ2 = 0 What is the alterative hypothesis? Select the correct symbols for each space. (Note this may view better in full screen mode.) HA: µ1 - µ2 ? v Select an answer Based on these hypotheses, find the following. Round answers to 4 decimal places. Test Statistic = p-value =Let x be a random variable that represents the pH of CVS brand water. The mean of this x distribution is u = 6.5 pH. A new company wants to sell its water at CVS locations. However, CVS management believes that the new brand will have a mean pH different from the CVS brand water. A random sample of 70 water samples were taken from this new company's water and it was found that the sample mean was 7.2 pH and the sample standard deviation was s = 2.5 pH. Do the data indicate that the new company's water has a mean pH level greater than 6.5, which is the pH of the CVS brand water? Use a 5% significance level. Identify the following in your answer. 1. Identify the null hypothesis Ho and alternate hypothesis H1 for the problem. 2. Identify and test statistic, the p-value and the calculator key used. Test Statistic (t): (Round to three decimal places) = p - value: (Round to four places) = Calculator key used: 3. Identify the significance level and determine if you reject or fail to reject…
- The t test for the mean difference between 2 related populations assumes that the population sizes are equal. sample variances are equal. population of differences is approximately normal or sample sizes are large enough. All of the above.What does it mean that the variance (computed by dividing by N) is a biased statistic?can you fill in the blanks
- Suppose a batch of steel rods produced at a steel plant have a mean length of 187 milimeters, and a Variance of 64. If 416 rods are sampled at random from the batch, what is the probability that the mean length all the sample rods would differ from the population mean by less than 0.65 millimeters? Round your answer to four decimal places.Determine the binomial distribution for which the mean is 4 and variance 3 and find its mode.* Let X is a Gaussian random variable with zero mean an variance o. Y = X. Find mean of Random Variable Y.