Low Gas Mileage. Suppose you buy a new car whose advertised mileage is 25 miles per gallon (mpg). After driving your car for several months, you find that its mileage is 21.4 mpg. You telephone the manufacturer and learn that the standard deviation of gas mileages for all cars of the model you bought is 1.15 mpg. a. Find the z-score for the gas mileage of your car, assuming the advertised claim is correct. b. Does it appear that your car is getting unusually low gas mileage?

A student who took Stat 2 last semester learns that their overall course score was at the 85th percentile. Assuming that a histogram of all the Stat 2 course scores from last semester follows the normal curve, this means that this student had a score that was how many SDs above the average score? Choose the answer that is closest. Group of answer choices 1.15 1.05 1.10 1.0      PreviousNext

Assume that you have been provided the following information for a sample of cars The covariance between weight and miles per gallon is equal to -4.9 pound-miles. The standard deviation of the cars' mileages is 7.75. The standard deviation of the cars' weights is 0.94. Estimate the correlation coefficient to the first decimal place.

Please answer d and e.

Ms. Gonzalez has recorded the test scores for each of her 25 students, She has calculated EX? = 320 and (EX) = 5,000, Calculate the estimated population standard deviation for her data. 1.98 2.24 O 5.00 O 3.95

The table below shows the frequency of AP Physics scores for a high school class. AP Score Frequency 1 4. 6. 3 4 Find the mean and median. O Mean = 1.67 and Median 2 Mean 5 and Median = 4 Mean 3 and Median Mean 3 and Median = 3 Mean 5 and Median 3

Help me find which A,B,C, or D is the correct answer to the last part please. The brain volumes ​(cm3​) of 50 brains vary from a low of 904 cm3 to a high of 1490 cm3. Use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 191.4 cm3​, assuming the estimate is accurate if it is within 15 cm3. The estimated standard deviation is 146.5 cm3.     A. The approximation is not accurate because the error of the range rule of​ thumb's approximation is greater than 15 cm3.   B. The approximation is not accurate because the error of the range rule of​ thumb's approximation is less than 15 cm3.   C. The approximation is accurate because the error of the range rule of​ thumb's approximation is greater than 15 cm3.   D. The approximation is accurate because the error of the range rule of​ thumb's approximation is less than 15 cm3.