Given are five observations for two variables, x and y. (Round your answers to two decimal places.) x, 3 12 6 20 14 Y₁ 55 40 55 10 15 (a) Estimate the standard deviation of when x 10. 8.76 X (b) Develop a 95% confidence interval for the expected value of y when x = 10. x to X (c) Estimate the standard deviation of an individual value of y when x = 10. (d) Develop a 95% prediction interval for y when x = 10.

A Scenario: Jimmy store sells large tins of Tom Tucker Coffee. The deli uses a periodic review system. Inventory is checked every 10 days which more orders are needed for tins. Order lead time is 3 days. Average demand is 7 tins, so average demand during the reorder period and order lead time (13) is 91 tins. Standard deviation of demand during the same 13 day period is 17 tins.1. Calculate the restocking level ( Assume the desired level is 90%)2. Suppose standard deviation of demand during the 13-day period drops to 4 tins. What happened to restocking level? Explain why?3. Draw a saw-tooth diagram. Beginning inventory level is equal to restocking level and the demand rate is a constant 7 tins per day. What is the safety stock level? What is the average inventory level?

i was wondering if i could get help with questions a and b

The mean exam score for 44. male high school students are 19.9 and the population standard deviation is 5.2. The mean exam score for 55female high school students is 19.4 and the population standard deviation is 4.9. At α=0.01​, can you reject the claim that male and female high school students have equal exam​ scores? Complete parts​ (a) through​ (e).   ​(a) Identify the claim and state H0 and Ha.   What is the​ claim?   A. Male high school students have lower exam scores than female students.   B. Male and female high school students have different exam scores.   C. Male and female high school students have equal exam scores.   D. Male high school students have greater exam scores than female students.   What are H0 and Ha​?   Find the critical​ value(s) and identify the rejection​ region(s). The critical​ value(s) is/are   Find the standardized test statistic z for μ1−μ2.

A standardized test is given to a sixth-grade class. Historically the mean score has been 151 with a standard deviation of 21. The superintendent believes that the standard deviation of performance may have recently decreased. She randomly sampled 23 students and found a mean of 161 with a standard deviation of 18.2898. Is there evidence that the standard deviation has decreased at the α=0.05 level? Step 1 of 5 : State of the hypotheses in terms of the standard deviation. Round the standard deviation to four decimal places when necessary Step 2 of 5 : Determine the critical value(s) of the test statistic. If the test is two-tailed, separate the values with a comma. Round your answer to three decimal places. Step 3 of 5 : Determine the value of the test statistic. Round your answer to three decimal places. Step 4 of 5 : Make the decision. Step 5 of 5 : What is the conclusion?

(1 point) A random sample of 110 observations produced a mean of x = 34.7 from a population with a normal distribution and a standard deviation o = 4.39. (a) Find a 99% confidence interval for u (b) Find a 95% confidence interval for (c) Find a 90% confidence interval for u

The expectation of X, which is also known as the mean or average, is E(X) = 7 and the Variance of X is var(X) =4. Using the equation  Y = 11X + 81.  What are the expected value E(Y), variance VAR(Y), and standard deviation SD(Y) of this expression.