HomeworkLib
Question

Question 5 The following table gives the frequency distribution of the amounts of telephone bills for August 2012 for a sample of 50 families. Amount of Telephone Bill (dollars) 40 to less than 70 70 to less than 100 100 to less than 130 130 to less than 160 160 to less than 190 Number of Families 12 10 16 Calculate the mean, variance, and standard deviation Round your answers to two decimal places. Mean Variance Standard deviation-$
math   Statistics-And-Probability   
0 0
Add a comment Improve this question Transcribed image text
Next > < Previous
Sort answers by oldest

Homework Answers

Answer #1

The classes for amount of bill and the number of families are given

Class "40 to less than 70" means 40 - 70 and number of families are nothing but the frequencies

Mean:

The formula to find mean is

fr Mean

Where f - frequency of class and x - mid point of class

The formula to find the midpoints x is,

Lower limit of class + Upper limit of class Midpoint(x)-

The midpoint of first class 40 - 70 is

40+70

Similarly the midpoints of the remaining classes are 85, 115, 145 and 175 respectively.

fx 55*3 + 85 12 115 10 145 *9+ 175 16 M ean = 3 +12+ 10+916

440128.8 Mean

Therefore, Mean = $128.8

Variance:

The formula to find the variance is,

Variance -(X - Mean )2f

(55 - 128.8)2 3 (85 128.8)212(115 128.8)210(145 - 128.8) 9(175 - 128.8)2 16 50 181587.31 7778 49

Therefore, variance is 1587.31

Standard deviation:

Standard deviation is the square root of variance

Standard deviation-VVariance = 1587.31-39.84

Therefore, the standard deviation is $39.84

1 1
Add a comment
Know the answer?
Add Answer to:
Question 5 The following table gives the frequency distribution of the amounts of telephone bills for...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

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 table gives the frequency distribution of the number of hours spent last week on...

    The following table gives the frequency distribution of the number of hours spent last week on cell phones (making phone calls and texting) by all 100 students of the tenth grade at a school. Hours per Week Number of Students 0 to less than 4 13 4 to less than 8 16 8 to less than 12 21 12 to less than 16 16 16 to less than 20 17 20 to less than 24 17 Find the mean, variance,...

  • Question 6 The following table gives the frequency distribution of the number of errors committed by...

    Question 6 The following table gives the frequency distribution of the number of errors committed by a college baseball team in all of the 45 games that it played during the 2011-12 season. Number of Errors Number of Games IT 14 Find the mean, variance, and standard deviation. (Hint: The classes in this example are single valued. These values of classes will be used as values of m in the formulas for the mean, variance, and standard deviation.) Round your...

  • The IRS was interested in the number of individual tax forms prepared by small accounting firms....

    The IRS was interested in the number of individual tax forms prepared by small accounting firms. The IRS randomly sampled 50 public accounting firms with 10 or fewer employees in the Dallas-Fort Worth area. The following frequency table reports the results of the study. Number of Clients Frequency 40 up to 70 3 70 up to 100 15 100 up to 130 22 130 up to 160 6 160 up to 190 4 Estimate the mean and the standard deviation....

  • The monthly utility bills in a city are normally distributed, with a mean of $100 and a standard deviation of $13

    The monthly utility bills in a city are normally distributed, with a mean of $100 and a standard deviation of $13. Find the probability that a randomly selected (a) less than $70. (b) between $85 and $100, and (c) more than $110. (a) The probability that a randomly selected utility bill is less than $70 is _______ 

  • 10. The following is a frequency table of a set of data: Fill in the missing...

    10. The following is a frequency table of a set of data: Fill in the missing information Grade Frequency relative frequency 90-100 A 16 80-89 65-79 50-64 Below 50 200 11. In a distribution that is skewed to the right, the mean is: Circle the correct answer. a) less than the median b) more than the median c) The mean and the median are equal in value d) There is inadequate information provided 12. For the given set of numbers...

  • Please also with explenations. Problem 1. The following frequency distribution reports the electric- ity cost for...

    Please also with explenations. Problem 1. The following frequency distribution reports the electric- ity cost for a population of 50 two-bedroom appartments in a certain area of Albuquerque, New Mexico during the month of May Electricity cost Mid point Frequency 80 up to 100 100 up to 120 120 up to 140 140 up to 160 160 up to 180 180 up to 200 90 12 16 a) Give the general formula for the arithmetic mean of a data set...

  • please answer all three questions. The monthly utility bills in a city are normally distributed, with...

    please answer all three questions. The monthly utility bills in a city are normally distributed, with a mean of $100 and a standard deviation of $16. Find the probability that a randomly selected utility bill is (a) less than $66, (b) between $81 and $90, and (c) more than $100. (a) The probability that a randomly selected utility bill is less than $66 is (Round to four decimal places as needed.)

  • The following table gives the frequency distribution of the daily commuting times (in minutes) from home to work for a s...

    The following table gives the frequency distribution of the daily commuting times (in minutes) from home to work for a sample of 25 employees of a company. Daily Commuting Time (mins) Number of Employees f Relative Frequency Cumulative Frequency Midpoint x xf (x - x̄)2 0 to less than 10 4 4/25 4 5 20 268.96 10 to less than 20 9 9/25 13 15 135 40.96 20 to less than 30 6 6/25 19 25 150 12.96 30 to...

  • The monthly utility bills in a city are normally distributed, with a mean of $100 and a standard deviation of $16.

    The monthly utility bills in a city are normally distributed, with a mean of $100 and a standard deviation of $16. Find the probability that a randomly selected utility bill is (a) less than $69. (b) between $84 and S90, and (c) more than $120 (a) The probability that a randomly selected utility bill is less than $69 is _______ (b) The probability that a randomly selected utility bill is between $84 and $90 is _______ (c) The probability that a randomly selected utility...

  • Question 3 You are given the frequency distribution table for the amounts spent on video rentals...

    Question 3 You are given the frequency distribution table for the amounts spent on video rentals (in dollars) during 2012 by 30 households randomly selected from those who rented videos in 2012 Amount Spent on Video Rentals (in dollars) FrequencyY 201-400 401-600 601 -800 801-1000 4 Prepare the cumulative frequency, cumulative relative frequency, and cumulative percentage distributions. Find the cumulative frequency, cumulative relative frequency, and cumulative percentage for the class corresponding to 601-800. Round your answer for the cumulative relative...

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