Question

Automobiles traveling on a road with a posted speed limit of 65 miles per hour are...

Automobiles traveling on a road with a posted speed limit of 65 miles per hour are checked for speed by a state police radar system. The following is a frequency distribution of speeds. Speed (miles per hour) Frequency 45 up to 55 50 55 up to 65 325 65 up to 75 275 75 up to 85 25 The standard deviation of this distribution is the closest to ____. 5.35 6.81 9.54 10.25

0 0
Add a comment Improve this question Transcribed image text
Answer #1

Solution:

Group Midpoint X Frequency f f*x x^2 f*(x^2)
45 to 55 50 50 2500 2500 125000
55 to 65 60 325 19500 3600 1170000
65 to 75 70 275 19250 4900 1347500
75 to 85 80 25 2000 6400 160000
SUM 675 43250 17400 2802500


= = 43250/675 = 64.0740740741

Variance =  

= [2802500/675] - [64.07407407412]

= 46.3648834019

Variance = 46.3648834019

Standard deviation = = = 6.81

Answer : 6.81

Add a comment
Know the answer?
Add Answer to:
Automobiles traveling on a road with a posted speed limit of 65 miles per hour are...
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. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
  • 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, Complete the cumulative frequency and relative frequency and answer the following questions based on it.( Round relative frequency up to 2 d.p.) Speed Miles per hour Frequency Cumulative frequency Relative frequency 50-55 2 55-60 4 60-65 5 65-70 10 70-75 9 75-80 5 Σf. . What is the Mid Point of third class Time left for this

  • A construction zone on a highway has a posted speed limit of 40 miles per hour....

    A construction zone on a highway has a posted speed limit of 40 miles per hour. The speeds of vehicles passing through this construction zone are normally distributed with a mean of 46 miles per hour and a standard deviation of 4 miles per hour. A. The fastest 10% of the vehicles passing through this construction zone are going at what speed?

  • 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 standard deviation is a.6.969 b.7.071 c.48.570 d.50.000

  • Police chase: A speeder traveling 45 miles per hour (in a 25 mph zone) passes a stopped police car which immediately ta...

    Police chase: A speeder traveling 45 miles per hour (in a 25 mph zone) passes a stopped police car which immediately takes off after the speeder. If the police car speeds up steadily to 60 miles/hour in 10 seconds and then travels at a steady 60 miles/hour, how long and how far before the police car catches the speeder who continued traveling at 45 miles/hour? (Fig. 32) 60+- 3 45 E 30 10 20 ? time (seconds) Fig. 32 Police...

  • A department of transportation's study on driving speed and miles per gallon for midsize automobiles resulted...

    A department of transportation's study on driving speed and miles per gallon for midsize automobiles resulted in the following data: Speed (Miles per Hour) 30 50 40 55 30 24 60 24 51 56 Miles per Gallon 28 24 24 22 30 33 21 Compute the sample correlation coefficient (to 2 decimals and enter negative value as negative number). 35 26 24 What can you conclude, based on your computation of the sample correlation coefficient? - Select your answer -...

  • A department of transportation's study on driving speed and miles per gallon for midsize automobiles resulted...

    A department of transportation's study on driving speed and miles per gallon for midsize automobiles resulted in the following data: Speed (Miles per Hour) Miles per Gallon Compute the sample correlation coefficient (to 2 decimals and enter negative value as negative number) 29513955 2924 60 25 50 55 28 24 2523 303221 36 25 25 What can you conclude, based on your computation of the sample correlation coefficient? Select your answer Select the correct interpretation for the sample correlation coefficient....

  • A department of transportation’s study on driving speed and miles per gallon for midsize automobiles resulted...

    A department of transportation’s study on driving speed and miles per gallon for midsize automobiles resulted in the following data: speed (miles per hour) 30 50 40 55 30 25 60 25 50 55 Miles per Gallon 28 25 25 23 30 32 21 35 26 25 Answer the following questions and calculate the following descriptive statistics: a) What type of data is it? (cross-sectional, time-series, or panel) b) How many observations in this data? c) Identify types of variables...

  • A department of transportation's study on driving speed and miles per gallon for midsize automobiles resulted in t...

    A department of transportation's study on driving speed and miles per gallon for midsize automobiles resulted in the following data Speed (Miles per our30 50 40 55 30 24 60 25 51 55 Miles per Gallon 28 24 24 23 30 32 21 35 26 25 Compute the sample correlation coefficient (to 2 decimals and enter negative value as negative number) What can you conclude, based on your computation of the sample correlation coefficient? - Select your answer- Select the...

  • 4. (12 pts) The speed limit on a highway is 70 miles per hour. A sample...

    4. (12 pts) The speed limit on a highway is 70 miles per hour. A sample of 8 cars are clocked at 69 mph, with a sample standard deviation of 5 miles per hour. Can we say, with at least 90 percent confidence that the average speed on the road is above 65? tcale = tarit Can we be at least 90 percent confidence that the average speed >70?

  • ASAP The speed of your automobile has a huge effect on fuel consumption. Traveling at 65...

    ASAP The speed of your automobile has a huge effect on fuel consumption. Traveling at 65 miles per hour (mph) instead of 55 mph can consume almost 20% more fuel. As a general rule, for every mile per hour over 55, you lose 2% in fuel economy. For example, if your automobile gets 30 miles per gallon at 55 mph, the fuel consumption is 21 miles per gallon at 70 mph. If you take a 400-mile trip and your average...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT