### Create a StudySoup account

#### Be part of our community, it's free to join!

Already have a StudySoup account? Login here

# Qnt Wk 1

AU

GPA 3.8

### View Full Document

## 16

## 0

## Popular in Course

## Popular in Department

This 7 page Study Guide was uploaded by tophomework Notetaker on Saturday November 14, 2015. The Study Guide belongs to a course at a university taught by a professor in Fall. Since its upload, it has received 16 views.

## Similar to Course at University

## Reviews for Qnt Wk 1

### What is Karma?

#### Karma is the currency of StudySoup.

#### You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 11/14/15

Exercises 80, 82, and 87 (Ch. 3) 80) Creek Ratz is a very popular restaurant located along the coast of northern Florida. They serve a variety of steak and seafood dinners. During the summer beach season, they do not take reservations or accept “call ahead” seating. Management of the restaurant is concerned with the time a patron must wait before being seated for dinner. Listed below is the wait time, in minutes, for the 25 tables seated last Saturday night. |28 |39 |23 |67 |37 |28 |56 |40 |28 |50 | |51 |45 |44 |65 |61 |27 |24 |61 |34 |44 | |64 |25 |24 |27 |29 | | | | | | 1. Explain why the times are a population. The times are considered a population because it includes all the tables that were used last Saturday night. 2. Find the mean and median of the times. Mean: 40.84 (all times added then divided by total of 25 tables) Median: Tables ordered from low to high |23 | |24 | |24 | |25 | |27 | |27 | |28 | |28 | |28 | |29 | |34 | |37 | |39 | |40 | |44 | |44 | |45 | |50 | |51 | |56 | |61 | |61 | |64 | |65 | |67 | Since there is not an even number on each side we add the 2 numbers from the middle which are 39 and 40 to get 79. We then divide this number (79) by 2 to receive the median number of 39.5. 3. Find the range and the standard deviation of the times. Range: The range is determined by the difference of the high and low data provided so we take the difference of 23 for the low and 67 for the high and come up with a range of 44. Standard deviation: This is the square root of the variance. Standard deviation is 14.84 82) The following frequency distribution reports the electricity cost for a sample of 50 two-bedroom apartments in Albuquerque, New Mexico during the month of May last year. |Electricity Cost |Frequency | |$ 80 up to $100 |3 | |100 up to 120 |8 | |120 up to 140 |12 | |140 up to 160 |16 | |160 up to 180 |7 | |180 up to 200 |4 | | Total |50 | 1. Estimate the mean cost. Arithmetic Mean x bar = ∑fM/n= 7060/50= 141.2 2. Estimate the standard deviation. s=√∑(X - X bar)2 / n-1 Answer: 11.9 s=√7008.64 /50-1 s=√7008.64 /49 s=83.7176206 /7 s= 11.95966 3. Use the Empirical Rule to estimate the proportion of costs within two standard deviations of the mean. What are these limits? Mean 141.2 Std. Dev 11.9 141.2 +/- (2) $11.9 141.2+11.9 = 165 141.2-11.9 = 117.4 95% of all costs will be between $117.4 and $165.0. 87) Refer to the Real Estate data, which reports information on homes sold in the Denver, Colorado, area last year. Price X- X bar (X-Xbar)2 1. Select the variable selling price. 1. Find the mean, median, and the standard deviation. Mean: Sum of all values in the sample/ 23215.8 Number of values in the sample 105 Answer: 221.1 Median: 213.6 Standard Deviation: 47.1 s=√∑(X - X bar)2 / n-1 s=√230767.6 /105-1 s=√230767.6 /105-1 s=480.382764 /10.198039 s= 47.1054057 2. Write a brief summary of the distribution of selling prices. The above data could symbolize the selling prices as having a large variance range. This being because the mean and median are different and median selling price being much lower than the mean selling price. 2. Select the variable referring to the area of the home in square feet. 1. Find the mean, median, and the standard deviation. Sum of all values in the sample/ 233500 Number of values in the sample 105 Answer: 2224 Median Answer: 2200 Standard Deviation Answer: 249 s=√∑(X - X bar)2 / n-1 s=√6430476 /105-1 s=√6430476 /104 s=2535.83832 /10.198039 s= 248.659406 2. Write a brief summary of the distribution of the area of homes. The above data can symbolize the homes being of comparable size based on the information of the median being only a little lower than the mean square footage and the standard deviation being 249sqft. Exercises 34, 36, and 38 (Ch. 5) 34) P(A1) = .20, P(A2) = .40, and P(A2) = .40. P(B1|A2) = .25. P(B1|A2) = .05, and P(B1|A3) = .10. Use Bayes' theorem to determine P(A3 | B1). (.40)(.10)/(.20)(.25) + (.40)(.05) + (.40)(.10) = .04/.11 = .3636 36) Dr. Stallter has been teaching basic statistics for many years. She knows that 80 percent of the students will complete the assigned problems. She has also determined that among those who do their assignments, 90 percent will pass the course. Among those students who do not do their homework, 60 percent will pass. Mike Fishbaugh took statistics last semester from Dr. Stallter and received a passing grade. What is the probability that he completed the assignments? A1= kids that did homework A2= kids that didn’t do homework B= kids that pass P(A1)= .80 P(A2)=.20 P(B׀ A1 )= .90 P(B׀ A2 )= .60 (.80)(.90)/(.80)(.90) + (.20)(.60) = .72/.84 = .8571 38) One-fourth of the residents of the Burning Ridge Estates leave their garage doors open when they are away from home. The local chief of police estimates that 5 percent of the garages with open doors will have something stolen, but only 1 percent of those closed will have something stolen. If a garage is robbed, what is the probability the doors were left open? P(A1) = .25 P(A2) = .75 P(B׀ A1 )= .05 P(B׀ A2 )= .01 (.25)(.90)/(.80)(.90) + (..75)(.01) = .225/.7275 = .3093 Exercises 45 and 62 (Ch. 6) 45) A Tamiami shearing machine is producing 10 percent defective pieces, which is abnormally high. The quality control engineer has been checking the output by almost continuous sampling since the abnormal condition began. What is the probability that in a sample of 10 pieces: 1. Exactly 5 will be defective? P(x=5) =10 5(.0010)(1-.0010)10 =..04995 2. 5 or more will be defective? P[x>=5] = 1-(P[X=0] + P[x=4] =1- [10c 0(.0010)(1-.0010)10 + 10c 0(.00101)(1-.0010)9 + 10c 0(.00104) (1-.0010)8 =0 62) Suppose 1.5 percent of the antennas on new Nokia cell phones are defective. For a random sample of 200 antennas, find the probability that: 1. None of the antennas is defective. P(X = 0) = 200C 0(0.0150)(1-0.015)200 = 0.04867 2. Three or more of the antennas are defective. P [X >= 3] = 1- (P[X = 0] + P [X = 1] + P [X = 2]) = 1 – [200C 0(0.0150) (1-0.015)200 + 200C 0(0.0151)(1-0.015)199 + 200C 0(0.0152)(1-0.015)198] =0.5785 Exercises 42 and 45 (Ch. 7) 42) The accounting department at Weston Materials, Inc., a national manufacturer of unattached garages, reports that it takes two construction workers a mean of 32 hours and a standard deviation of 2 hours to erect the Red Barn model. Assume the assembly times follow the normal distribution. 1. Determine the z values for 29 and 34 hours. What percent of the garages take between 32 hours and 34 hours to erect? Z = (X - µ)/ σ = (29 – 32)/ 2 = -1.5 Z = (34 – 32) = 1 P [32 < X < 34] = P [(32 – 32)/2 < (X - µ)/ σ < (34 – 32)/2] = P [0 < Z < 1] = 0.3413 2. What percent of the garages take between 29 hours and 34 hours to erect? P [29 < X < 34] = P [(29 – 32)/2 < (X - µ)/ σ < (34 – 32)/2] = P [-1.5 < Z < 1] = 0.7745 3. What percent of the garages take 28.7 hours or less to erect? P[X

### BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.

### You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

## Why people love StudySoup

#### "There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."

#### "When you're taking detailed notes and trying to help everyone else out in the class, it really helps you learn and understand the material...plus I made $280 on my first study guide!"

#### "I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"

#### "It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

### Refund Policy

#### STUDYSOUP CANCELLATION POLICY

All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email support@studysoup.com

#### STUDYSOUP REFUND POLICY

StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here: support@studysoup.com

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to support@studysoup.com

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.