A researcher believes the mean wait times of two call centers are statistically different. The researcher independently samples 100 customers from each of two call centers. The sample mean wait times are as follows: xˉ1=8.5\bar{x}_1=8.5, xˉ2=7.5\bar{x}_2=7.5  The corresponding population standard deviations are known to be: σ1=4\sigma_1=4, σ2=3\sigma_2=3 Calculate the test statistic (t-score or z-score) using the appropriate test.

A circuit breaker manufacturer claims that, under specified test conditions, its breakers trip at a mean current of at least 25 A. A quality-control engineer believes that the true mean trip current is lower than 25 A. The population standard deviation is known to be 4 A. The engineer randomly tests 64 circuit breakers and observes a sample mean trip current of 24 A. Calculate the p-value associated with the sample result. (Hint: Use the 68-95-99.7 rule)

The right lung has 

Which of the following affect a disinfectant’s effectiveness? [answer1] Regarding disinfectant, what does “contact time” refer to? [answer2]

[answer1] refers to the ability of a suture to return to its original packaged form. In an ideal suture,  you want this ability to be [answer2]

Sketch a graph of a function with the following characteristics  – translate to a number line for each derivative.   The function f has only ONE point of discontinuity and it’s domain is [-4,

Evaluate each indeterminate limits, if they exist. State which indeterminate form you have, then show analytic work to evaluate (graph/table are NOT allowed for work but can be a check). For credit you MUST show all work on paper and include 1) which indeterminant form; 2) proper limit notation throughout the work; 3) indication when L’H is applied   a.

Which of the following are functional diseases?    1.  diabetes    2.  cancer    3.  leprosy    4.  epilepsy

Type your responses to this question below.  Label each part in your response. Is there a difference in college students’ GPA in the Fall semester compared to the Spring semester? A random sample of 80 college students reported their GPA from the most recent Fall Semester and most recent Spring semester. The 95% confidence interval to estimate the mean difference (Fall – Spring) in college students’ GPA in the Fall and Spring semesters was determined to be (-0.348, 0.932).  Does this scenario involve matched pairs or two independent samples? (2 points) Fully interpret the interval in context. (8 points) Does the interval support that the mean GPA for college students during the Fall semester is significantly different than in the Spring semester? Briefly explain your answer. (4 points)

Use of CrunchIt is required for this question. Round answers to three decimal places. A random sample of experienced drivers participated in a simulator study to assess reaction time under two different lighting conditions. Each driver completed the same driving course twice—once during simulated daylight and once during simulated nighttime conditions. For each participant, the order in which they experienced the conditions was randomly determined. The reaction time (in seconds) to unexpected obstacles for each person was recorded for each condition. The data is summarized below. Difference  n mean standard deviation daylight – nighttime 18 0.845 1.572   Determine the 95% confidence interval to estimate the mean difference in reactions times under the two conditions: ([lower], [upper]) What is the margin of error for your interval? [b]