A random sample of vehicle speeds were collected. Use the data to test the claim that the mean vehicle speed is more than 40 mph. Use a 0.05 level of significance. • Use the P-value method • Show all 5 steps x = 42 mph s = 7 mph n = 34

*PLEASE show in excel A different investigator conducts a second study to investigate whether there is a difference in mean PEF in children with chronic bronchitis as compared to those without.  Data on PEF are collected and summarized below.  Based on the data, is there statistical evidence of a lower mean PEF in children with chronic bronchitis as compared to those without?  Run the appropriate test at a=0.05.    Group Number of Children Mean PEF Std Dev PEF   Chronic Bronchitis 25 281 68   No Chronic Bronchitis 25 319 74           Step 1. Set up hypotheses and determine level of significance.   Ho:         H1:         alpha:                   Step 2. Select the appropriate test statistic and give its formula.                                           Step 3. Set up decision rule.                             Step 4. Compute the test statistic                                               Step 5. Conclusion.

Find the proportion of N.d. observations with a zz-score between z_1 =z1​= -2.45 and z_2 =z2​= 2.71. Give your answer to four decimal places.

a baker makes cookies n= 50, mean = 10, s = 2. what is the lower bound for a 90% confidience interval for the mean number of cookies per bin?