Class interval | Class mark | Frequency |
7.5-12.5 | 10 | 3 |
12.5-17.5 | 15 | 9 |
17.5-22.5 | 20 | 14 |
22.5-27.5 | 25 | 7 |
27.5-32.5 | 30 | 1 |
Mean = Sum of (Class mark x frequency) / Sum of frequency
= (10x3 + 15x9 + 20x14 + 25x7 + 30x1) / (3+9+14+7+1)
= 650/34
= 19.1
Variance = Sum of [(Class mark - mean)2 x frequency] / Sum of frequency
= [(10 - 19.1)2x3 + (15-19.1)2x9 + (20-19.1)2x14 + (25-19.1)2x7 + (30-19.1)2x1]/34
= 773.5/34
= 22.8
Standard deviation =
= 4.8
Thirty-four automobiles were tested for fuel efficiency (in miles per gallon). The following frequency distribution was...
5. Thirty automobiles were tested for fuel efficiency in miles per gallon. The following frequency distribution was obtained. Calculate the mean. Class Boundaries Frequency 7.5-12.5 12.5-17.5 17.5-22.5 225-275 27.5-32.5 a 552 b.20.33 c.610 d. 25
Question 3 of 4 (1 point) Twenty-nine automobiles were tested for fuel efficiency (in miles per gallon). The following frequency distribution was obtained. Find the variance and standard deviation. Round your answers to one decimal place. 3.2 Section Exercise 20 Class boundaries 7.5-12.5 12.5-17.5 17.5-22.5 22.5-27.5 27.5-32.5 Frequeney 4 Download data Variance- Standard deviation -
Problem 1 (18 points) Suppose the distribution of fuel efficiency (miles per gallon (mpg) in highway driving) for a sample of cars has a mound-shaped and symmetric distribution with mean x =38 and standard deviation s = 10 points. Illustrate your answers with graphs. a. Calculate the percent of cars whose fuel efficiency is less than 48 mpg. b. Calculate the percent of scores that are between 28 and 68 mpg. c. Calculate the 16th percentile of the data.
only the questions with ticks, that is question 13 and
14.
Section 3-2 Measures of Central Tendency 111 Find the (a) mean, (b) median, (e) mode, and d) midrange for the distances of the home runs for obtained. (The data in this exercise will be used in Exercise 20 in Section 3-3.) and Sosa, using the data in Exercise 18 in Class boundaries Compare the means. Decide if the means are anproximately equal or if one of the players is...
Question 5 (1 point) Following are the fuel efficiency, in miles per gallon, for a sample of convertibles. Calculate the sample variance. 25, 18, 22, 20, 21 Write only a number as your answer. Round to one decimal place (for example 8.3) Your Answer:
Problem 1 (18 points) Suppose the distribution of fuel efficiency (miles per gallon (mpg) in highway driving) for a sample of cars has a mound-shaped and symmetric distribution with mean X =38 and standard deviations 10 points. Illustrate your answers with graphs. a. Calculate the percent of cars whose fuel efficiency is less than 48 mpg. b. Calculate the percent of scores that are between 28 and 68 mpg. c. Calculate the 16th percentile of the data.
The fuel efficiency in miles per gallon of all BMW 320i’s is approximately normally distributed with a mean of 25 and a standard deviation of 2. A dealer receives a shipment of a random sample of 320i’s (random with respect to mpg) from the factory. Hint: look at the sample sizes and think about which tables you’d need to use for these problems. (a) Find the probability that average fuel efficiency is less than 24 mpg if the dealer receives...
Sports car or convertible? The following table presents the fuel efficiency, in miles per gallon, for a sample of convertibles and a sample of sports cars. Convertible Model MPG Sports Model MPG BMW 328i Mitsubishi Lancer Evolution Toyota Camry Solara Ford Mustang V6 Volkswagen Eos MINI Cooper Saab 9-3 Volkswagen GTI Honda Civic Si BMW 135i 23 Mazda Mazdaspeed Subaru Impreza WRX STI 24 Send date to Excel Part 1 of 2 Part 2 of 2 (b) Find the sample...
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Fuel consumption is commonly measured in miles per gallon (mi/gal). An agency designed new fuel consumption tests to be used starting with 2008 car models. Listed below are randomly selected amounts by which the measured MPG ratings decreased because of the new 2008 standards. Find the range, variance, and standard deviation for the sample data. Is the decrease of 4 mi/gal unusual? Why or why not? 1 2 2 2 4 3 3...
number 14
Fuel consumption is commonly measured in miles per gallon (milgal). An agency designed new fuel consumption tests to be used starting with 2008 car models. Listed below are randomly selected amounts by which the measured MPG ratings decreased because of the new 2008 standards. Find the range, variance, and standard deviation for the sample data. Is the decrease of 4 mi/gal unusual? Why or why not? 2 2 3 1 3 3 4 2 2 2 2 1...