The burning rates of two different solid-fuel propellants used in aircrew escape systems are being studied. It is known that both propellants have the same standard deviation of burning rate; o1 = 02 = 3 centimetres per %3D second. Two random samples of n1 = n2 = 20 are tested; the sample mean burning rates are 24.3 and 24 centimetres per second respectively. If you want to test the hypothesis that the burning rates of the 2 propellants are different, what is the value of Zcalc? In computing zcalc, use the hypothesis test with respect to µl – µ2.Please report your answer in 2 decimal places.

Solve question 9, Part A, Part B and Part C only.

Denny studied factors affecting cardiovascular reactivity to a postural change in a sample of healthy men and women. Change in systolic blood pressure (SBP) from supine to standing position was used as the measure of cardiac reactivity in a sample of 842 adults. Supine measurement of blood pressure was taken after participants had lain on an examination table for 15 minutes. Blood pressure was determined every 30 seconds using a Dinamap device for 2 minutes, and the measurements were averaged. Participants then stood up immediately, and additional measurements were made for another 2 minutes. Below is a table describing the characteristics of Denny’s sample: Which measures of dispersion, if any, are presented in this table (Ranges, SDs)? If age is normally distributed, approximately what percent of the sample would be younger than 50? If BMI is normally distributed, approximately what percent of the sample would have a BMI higher than 33.1?

Question4: The times for untrained rats to run a standard maze has a normal distribution where the times are measured in seconds. The researcher hopes to show that training improves the times. A sample of 9 rats were selected and the time to run a standard maze before and after training were measured in seconds and shown below. Does the data support the researcher’s hypothesis? Conduct a hypothesis test at 5% significant level (specify 4 steps).

Part 1 of 4 Suppose that you randomly survey death records for people born in 1900 in Virginia and compared the life span of two different ethnicities. Of the 132 individuals sampled from ethnicity 1, the mean life span was 58.5 years with a standard deviation of 16.9 years. Of the 191 individuals sampled from ethnicity 2, the mean life span was 54.3 years with a standard deviation of 10.3 years. Conduct a hypothesis test with a 7% level of significance to see if the mean life spans in Virginia were the same for the two ethnicities. Step 1: State the null and alternative hypotheses. Ho: 12V✓0 Ha: 1₂V0 (So we will be performing a two-tailed Part 2 of 4 Step 2: Assuming the null hypothesis is true, determine the features of the distribution of the differences of sample means. The differences of sample means are t-distributed and distribution standard deviation Question Help: Post to forum C Submit Part test.) 06 ✓✓with distribution mean MacBook Pro Search or type URL ...........

Question 20. part b. Nationally, patients who go to the emergency room wait an average of 7 hours to be admitted into the hospital. Do patients at rural hospitals have a lower waiting time? The 14 randomly selected patients who went to the emergency room at rural hospitals waited an average of 5.8 hours to be admitted into the hospital. The standard deviation for these 14 patients was 1.7 hours. What can be concluded at the the αα = 0.05 level of significance level of significance? C.)The test statistic ?, z or t  = ____ (please show your answer to 3 decimal places.) D.)The p-value = ______ (Please show your answer to 4 decimal places.) E.) The p-value is ?, ≤ , >  α