4. A researcher wishes to determine whether Toyota Corollas use more gas than Honda Civics after 10,000 miles of use. Use the computer output below to test the claim at a 1% significance level that Corollas use more gas on average than Civics (Note: we made the comparison: μcorolla - μcivic).

test stat, df, p-value, mean dif, st. error,
2.67, 44, 0.005, 4.38, 1.92

Do not reject the null; The test does not show a significant difference between the two cars.

Reject the null; The test shows the Corolla consumes more gas.

Do not reject the null; The test shows he Civic use more gas than the Corolla.

Reject the null; The test shows the Civic consumes more gas.

Do not reject the null; The test shows a significant difference between the two cars.

None of these

Problen 6.70. The marker on your new car indicates that you have already run the first 3,000 miles, at which point the manufacturer recommends a general overhaul. You take your car to a recognized garage and request a review. Upon arrival in the garage there are 8 mechanics available, two of which are new. For a new mechanic, the time it takes to perform the overhaul is a random variable that follows a normal distribution with an expected value of 1 hour and a standard deviation of 5 minutes. For an experienced mechanic, the time to perform the overhaul follows an exponential distribution with an expected value of 40 minutes.

 If your car will be randomly assigned to any of the available mechanics,

1. What is the probability that your car is ready in less than 1 hour? 


2. If your car is ready in less than an hour, what is the probability that it was serviced by an experienced mechanic? 

We are interested in exploring the relationship between the weight of a vehicle and its fuel efficiency (gasoline mileage). The data in the table show the weights, in pounds, and fuel efficiency, measured in miles per gallon, for a sample of 12 vehicles.

g.)For the vehicle that weighs 3000 pounds, find the residual

(y − ŷ).

(Round your answer to two decimal places.) _________

I.)Remove the outlier from the sample data. Find the new correlation coefficient and coefficient of determination. (Round your answers to two decimal places.)

correlation coefficient _____

Correlation of determination _____

Find the new best fit line.  (Round your answers to four decimal places.)

ŷ = ______    x + _______

1.

A student bikes to school by traveling first dN = 1.00miles north, then dW = 0.500miles west, and finally dS = 0.200miles south.

If a bird were to start out from the origin (where the student starts) and fly directly (in a straight line) to the school, what distance db would the bird cover?

Express your answer in miles.

2.

You will now find the same quantity algebraically, without the need to use much geometry. Take the north direction as the positive y direction and east as positive x. The origin is still where the student starts biking.

Let d? N be the displacement vector corresponding to the first leg of the student's trip. Express d? N in component form.

Express your answer as two numbers separated by a comma (e.g., 1.0,2.0). By convention, the x component is written first.

How to give an explanation for each of the descriptive statistics tables below?

MPG
36.3
41
36.9
37.1
44.9
36.8
30
37.2
42.1
36.7
32.7
37.3
41.2
36.6
32.9
36.5
33.2
37.4
37.5
33.6

1. The EPA collects data on 20 cars and calculates their gas mileage in miles per gallon (MPG).

a) Make a histogram for the data with the first class of [30, 32).

b) Find the mean, the median and the standard deviation of the data.

c) Find the Q1, Q3, IQR and fences.

d) Using the modified box-plot methodology determine if there are any outliers and justify. You do not have to make the box-plot!

e) Create a new variable by subtracting the mean from each observation and then dividing the difference by the standard deviation.

f) Find the mean, median and standard deviation of the new variable.

g) In one or two sentences, describe the original data.

Though the develoment of railroads began in the first half of the 189th century, their true impact was not experienced until the Gilded Age. Railroads broke down many barriers withtin the country. Physically, people and products could travel year-round further and faster. Before people rarely travel more than 100 miles from the place they were born. Culturally, ideas and differing people would influence the country. This is the first time that a truly American culture began to develop instead of just regional identities. Lastly, business opportunities expanded and a national market was developed. Now goods produced in one area of the country could easily be transportd to another without the need of a water route.

Railroads became the model for all the big businesses that followed. What was that model and give two examples how other businesses adopted it?

A kinesiologist wanted to investigate the effect of temperature and humidity on human performance. He found 28 college students and randomly assigned them to four different conditions, during which they were to walk at their normal pace on a treadmill for 60 minutes. He measured how far, in miles, they walked. The conditions varied in temperature (normal temperature/high temperature) and humidity (normal humidity/high humidity). The data are presented below, and SSwithin = 1.58. Do all hypothesis testing steps and compute effect sizes. Note that T = Σx.  

Normal Temperature, Normal Humidity

n = 7

M = 3.00

T = 21

Normal Temperature, High Humidity

n = 7

M = 2.80

T = 19.60

High Temperature, Normal Humidity

n = 7

M = 2.80

T = 19.60

High Temperature, High Humidity

n = 7

M = 2.00

T = 14

A car company is considering a new engine filter for its new hybrid automobile line. But it does not want to switch to the new brand unless there is evidence that the new filter can improve fuel economy for the vehicle (miles per gallon). The experimental design is set up so that each of the 10 cars drive the same course twice - once with the old filtration system and once with the new version. The data collected is shown below:

Conduct a hypothesis testing to determine whether the new filtration system is superior. Provide the p-value from your analysis.

In 2017, the entire fleet of light‑duty vehicles sold in the United States by each manufacturer must emit an average of no more than 86 milligrams per mile (mg/mi) of nitrogen oxides (NOX) and nonmethane organic gas (NMOG) over the useful life (150,000 miles of driving) of the vehicle. NOX + NMOG emissions over the useful life for one car model vary Normally with mean 82 mg/mi and standard deviation 5 mg/mi.

(a) What is the probability that a single car of this model emits more than 86 mg/mi of NOX + NMOG? (Enter your answer rounded to four decimal places.)

(b) A company has 25 cars of this model in its fleet. What is the probability that the average NOX + NMOG level x¯ of these cars is above 86 mg/mi? (Enter your answer rounded to four decimal places.