Question

The following is the frequency distribution for the speeds of a sample of automobiles traveling on...

The following is the frequency distribution for the speeds of a sample of automobiles traveling on an interstate highway.

Speed (mph)

Frequency

50−54

  2

55−59

  4

60−64

  5

65−69

10

70−74

  9

75−79

  5

35

The mean is 67

How to find the Variance?

Homework Answers

Answer #1

Ans.

Speed(mph) frequency(fi) midpoint (xi)
50-54 2 52 225 450
55-59 4 57 100 400
60-64 5 62 25 125
65-69 10 67 0 0
70-74 9 72 25 225
75-79 5 77 100 500
Sum = 35 1700

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Create the appropriate frequency distribution graph by hand. Below are the speeds of cars clocked by...
Create the appropriate frequency distribution graph by hand. Below are the speeds of cars clocked by radar on a 35-mph zone of a road on a particular afternoon. 99, 96, 94, 91, 90, 90, 89, 87, 85, 84, 82, 80, 79, 78, 77, 76, 34, 75, 75, 74, 74, 72, 70, 69, 68, 68, 68, 66, 66, 65, 63, 63, 60, 59, 58, 58, 54, 50, 48, 46, 42, 38, 33, 12
Approximate the mean for following frequency table. Data Frequency 60 - 64 13 65 - 69...
Approximate the mean for following frequency table. Data Frequency 60 - 64 13 65 - 69 22 70 - 74 13 75 - 79 7 80 - 84 5 85 - 89 4 90 - 94 2 95 - 99 1 100 - 104 1 mean = Report answer accurate to one decimal place. Approximate the mean for following GFDT. Data Frequency 50 - 54 1 55 - 59 4 60 - 64 5 65 - 69 14 70 -...
A police officer is concerned about speeds on a certain section of Interstate 95. The data...
A police officer is concerned about speeds on a certain section of Interstate 95. The data accompanying this exercise show the speeds of 40 cars on a Saturday afternoon. Highway Speed: 73 68 67 74 74 70 68 73 65 69 67 63 66 64 67 65 70 64 63 61 62 63 63 66 64 62 65 62 70 62 66 64 67 61 69 66 61 70 65 61 a. The speed limit on this portion of Interstate...
There is concern about the speed of automobiles traveling over US 131. For a random sample...
There is concern about the speed of automobiles traveling over US 131. For a random sample of seven automobiles radar indicated the following speeds, in miles per hour:80, 74, 69, 78, 87, 72, and 70. Assuming a normal population distribution, find the margin of error of a 95% confidence interval for the mean speed of all automobiles traveling over this stretch of highway. ( mean= 75.7143, S=6.3957)
A police officer is concerned about speeds on a certain section of Interstate 95. The data...
A police officer is concerned about speeds on a certain section of Interstate 95. The data accompanying this exercise show the speeds of 40 cars on a Saturday afternoon. Highway speeds 65 60 63 68 66 70 70 68 69 65 61 68 61 67 65 61 69 70 67 65 60 69 70 68 61 60 66 64 65 68 61 62 62 60 69 62 62 62 69 62 a. The speed limit on this portion of Interstate...
4.) Find the measures of center for following. Data Frequency 40 - 44 13 45 -...
4.) Find the measures of center for following. Data Frequency 40 - 44 13 45 - 49 18 50 - 54 15 55 - 59 10 60 - 64 6 65 - 69 6 70 - 74 4 75 - 79 1 80 - 84 2 5.) Adult men have heights with a mean of 69.0 inches and a standard deviation of 2.8 inches. Find the z-score of a man who is 62.5 inches tall. (to 4 decimal places)
Find the measures of center for the following: Data Frequency 30-34 2 35-39 4 40-44 6...
Find the measures of center for the following: Data Frequency 30-34 2 35-39 4 40-44 6 45-49 11 50-54 18 55-59 15 60-64 11 65-69 1 70-74 5 mode= median= mean (round to 4 decimal places)=
29 74 51 42 55 75 74 74 79 74 43 79 55 74 25 4...
29 74 51 42 55 75 74 74 79 74 43 79 55 74 25 4 69 78 74 52 76 74 4 64 76 79 69 77 79 24 75 78 74 69 65 80 72 79 62 79 8 66 79 43 76 72 45 73 5 79 74 74 75 38 60 2 74 78 79 73 63 45 74 64 63 75 62 43 67 72 62 62 54 3 45 79 62 64 75 72...
7. using the following, construct a complete frequency distribution include the mean, variance, standard deviation. Also...
7. using the following, construct a complete frequency distribution include the mean, variance, standard deviation. Also graph the frequency histogram, polygon and ogive. indicate modal class, median class and describe the distribution. class limits frequency 28-34 4 35-41 12 42-48 20 49-55 10 56-62 4 9. find the weighted mean for three exams if the first one was worth 25% and the student received a 92, the second was worth 40% and the student received a 86 and the third...
The following scores represent a sample of final examination grades for a statistics course 23 60...
The following scores represent a sample of final examination grades for a statistics course 23 60 98 32 57 74 52 70 82 69 74 63 80 62 80 77 81 95 41 65 92 85 85 61 36 79 55 76 52 10 64 75 78 25 80 48 83 64 88 82 81 67 41 71 67 54 34 72 74 43 60 78 84 89 76 84 17 90 15 79 a) Compute the 20th percentile of...