a series of 20 samples of size 4 has been drawn from a project. the measure of interest has an average of 23.7 and the average range within the sample is 3.51 determine the control chart upper limit for x-bar

A sample of 14 participants took part in a hearing experiment. Among other things, the absolute hearing threshold (in decibels) was measured for each participant. The 14 measurements were as follows: 25, 22, 18, 35, 37, 34, 18, 18, 39, 39, 39, 36, 36, 33 Send data to calculator Draw the histogram for these data using an initial class boundary of 17.5 and a class width of 7. Note that you can add or remove classes from the figure. Label each class with its endpoints. Frequency 7+ 6+ 5- 4+ 3+ 0 0 0 0 Absolute hearing threshold (in decibels) 0 17.5 0:00 00:0 X

Suppose that you wish to estimate the difference between mean pH measurements of rainfalls in two different locations, one in relatively unpolluted area and the other in an area subject to heavy air pollution. You want to be 95% confident that the margin of error for the difference between mean pH of rainfalls in relatively unpolluted area and mean pH of rainfalls in an area subject to heavy air pollution will not exceed 0.1 pH. How many rainfalls (pH measurements) must be included in each sample? Assume that the variance of pH measurements in a relatively unpolluted area is equal to 2 = 20, and the variance of pH measurements in an area subject to heavy pollution is equal to 2 = 0.25, and samples will be of equal size (n = n₂ = n). 2 It is supposed that values of pH in rainfalls are normally distributed in polluted and unpolluted areas. The number of rainfalls (pH measurements) that must be included in each sample is

Suppose that you had collected the following sample data (in inches) on the diameters of tree trunks, measured at waist level and growing at 2000’ elevation in the Cascade Mountains: 9.0, 6.2, 6.5, 7.0, 10.5 and 8.8. The sample Inter Quartile Range is: (a) 5.5 (b) 4.5 (c) 3.5 (d) 2.5 (e) 4.0 (f) None of the above

Please answer the following question by stating conditions and test required. Please show how to answer using graphing calculator if possible.