In a survey it is found that housewives watch TV 3 hours a day on average. It is assumed that the duration of housewives watching TV in a day obeys a normal distribution with σ = 9. On a certain day a housewife is chosen randomly a. Find the probability that she watches TV less than 3 hours. b. Find the probability that she watches TV between 1 hour and 2 hours. c. In a certain day it is observed that 100 housewives watch TV more than 2 hours. Find the number of people participated in this survey

In a survey it is found that housewives watch TV 3 hours a day on average. It is assumed that the duration of housewives watching TV in a day obeys a normal distribution with σ = 9. On a certain day a housewife is chosen randomly a. Find the probability that she watches TV less than 3 hours. b. Find the probability that she watches TV between 1 hour and 2 hours. c. In a certain day it is observed that 100 housewives watch TV more than 2 hours. Find the number of people participated in this survey

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

See similar textbooks

Similar questions

NEED ASAPIndicate the units and draw the graph. Round off to four decimals or in lowest term if fraction.
ssume that 33.2% of people have sleepwalked. Assume that in a random sample of 1454 adults, 523 have sleepwalked. a. Assuming that the rate of 33.2% is correct, find the probability that 523 or more of the 1454 adults have sleepwalked. b. Is that result of 523 or more significantly high?
Assume that the amount of time until a kid gets bored and wants to leave a playground can be modeled using exponential distribution. Given that 5 kids leave a particular playground on average per hour, if a kid has already played 10 minutes there what is the probability he will have spent at least a total of 25 minutes before he leaves? OA. 0.2865 OB. 0,7135 OC 0.8755 OD.0.1245
Suppose x is a uniform random variable with values ranging from 40 to 90. Find the probability that a randomly selected observation exceeds 55.
Let X represent the full height of a certain species of tree. Assume that X has a normal probability distribution with a mean of 58.2 ft and a standard deviation of 4.8 ft. A tree of this type grows in my backyard, and it stands 56.8 feet tall. Find the probability that the height of a randomly selected tree is as tall as mine or shorter. P(X<56.8)= My neighbor also has a tree of this type growing in her backyard, but hers stands 61.1 feet tall. Find the probability that the full height of a randomly selected tree is at least as tall as hers. P(X>61.1)= Enter your answers as decimals accurate to 4 decimal places.
Researchers have shown that the num-ber of successive dry days that occur after a rainstorm for particular regions of Catalonia, Spain, is a random variable thatis distributed exponentially with a mean of 8 days. Source:International Journal of Climatology.a. Find the probability that 10 or more successive dry daysoccur after a rainstorm.b. Find the probability that fewer than 2 dry days occur aftera rainstorm.
Tyson Corp. stock has returns of 3%, 18%, -24%, and 28% for the past four years. Based on this information, what is the 99% probability range for any one given year? Select one: Oa 24.5 to 34.3% O b.-61.7 to 74.2% OC.-8.4 to 11.7% Od.-16.4 to 28.9% e. 39.0 to 51.5%
Assume that different groups of couples use a particular method of gender selection and each couple gives birth to one baby. This method is designed to increase the likelihood that each baby will be a girl, but assume that the method has no effect, so the probability of a girl is 0.5. Assume that the groups consist of 44 couples. Complete parts (a) through (c) below. a. Find the mean and the standard deviation for the numbers of girls in groups of 44 births. The value of the mean is (Type an integer or a decimal. Do not round.) The value of the standard deviation is o = (Round to one decimal place as needed.) b. Use the range rule of thumb to find the values separating results that are significantly low or significantly high. Values of girls or fewer are significantly low. (Round to one decimal place as needed.) Values of girls or greater are significantly high. (Round to one decimal place as needed.) c. Is the result of 35 girls a result that is significantly high? What does it…
Assume that different groups of couples use a particular method of gender selection and each couple gives birth to one baby. This method is designed to increase the likelihood that each baby will be a girl, but assume that the method has no effect, so the probability of a girl is 0.5. Assume that the groups consist of 30 couples. Complete parts (a) through (c) below. a. Find the mean and the standard deviation for the numbers of girls in groups of 30 births. The value of the mean is u = (Type an integer or a decimal. Do not round.).
The random variable x represents the number of emails a student receives on a day. Assume it has a Poisson distribution with a mean of 14.3 emails. Find the probability that in a random day the student receives 3 emails. Round your answer to four decimal places.
The probability that a randomly selected student from a college is a senior is .20, and the joint probability that the student is a computer science major and a senior is .03. Find the condi- tional probability that a student selected at random is a computer science major given that the student is a senior.
In a given company, employee should sign in using the biometric time clock. There are 3 devices in thecompany and the probability that it works is 95%.Let x be the random variable of the number of devices working at a given day.1. Construct the probability distribution of x.2. Find the mean value and interpret it.3. Find the standard deviation and interpret it.