# The tread life is normally distributed with a standard deviation of 295.5 kilometers

23,297 results

### statistics

The tread life a certain brand of tires is known to be normally distributed with a mean of 60,000 miles and a standard deviation of 5,000 miles. The company wishes to set the warranty so that only 4% of the tires will need to be replaced. What should the warranty mileage be?

### statistics

The tread life a certain brand of tires is known to be normally distributed with a mean of 60,000 miles and a standard deviation of 5,000 miles. The company wishes to set the warranty so that only 4% of the tires will need to be replaced. What should the warranty mileage be?

### statistics

It is claimed that an automobile is driven on the average more than 20,000 kilometers per year. Random sample of 10 automobile owners are asked to keep a record of the kilometers they travel. If the sample mean and standard deviation of automobile driven are found to be 23,500...

### math

A chemist test involves measuring two independent quantities A and B, the expressing the results of the test as C such that C= 3A-0.5B. Give that A is normally distributed with mean 10 and standard deviation of 1, and B is also normally distributed with mean 34 and standard ...

### prob and stats

The tread lives of the Super Titan radial tires under normal driving conditions are normally distributed with a mean of 34000 mi and a standard deviation of 1700 mi. (a) What is the probability that a tire selected at random will have a tread life of more than 35071 mi? Round ...

### math

Eldon received 72 on his first calculus test. The marks were normally distributed with a mean of 60 and a standard deviation of 8. He received 80 on the next test, which was normally distributed with a mean of 75 and a standard deviation of 6. Which was the better mark, ...

### statistics

A survey found that women's heights are normally distributed with mean 63.5 in. and standard deviation 2.3 in. The survey also found that men's heights are normally distributed with a mean 68.7 in. and a standard deviation 2.8. (a) Most of the live characters at an amusement ...

### Statistics Please help me :(

I have no idea where to even start. Suppose heights of men are normally distributed with a mean 69.0 inches and standard deviation 2.8 inches. How many of a group of 1000 men would you expect to be between 70 and 72 inches tall? Round to the nearest whole number. Suppose ...

### math

a tire manufacturer believes that the tread life of its tires are normally distributed and will lst an average of 60,000 miles with a standard deviation of 3,000 miles. sixty-four randomly selected tires were tested and the average miles where the tire failed were recorded. ...

### Statistics

find the 90% confidence interval for the variance and standard deviation of a sample of 16 and a standard deviation of 2.1 Assume the variable is normally distributed.

### Statistics

9 points) In a normally distributed data set, find the value of the standard deviation if the following information is given. a. The mean is 226.2. x = 230. z = 0.2. Standard deviation

### Statistics

he life expectancy of a lung cancer patient treated with a new drug is normally distributed with a mean of 4 years and a standard deviation of 10 months

### statistics

Section 5.3: Normal Distributions: Finding Values Answer the questions about the specified normal distribution. Q1: The lifetime of ZZZ batteries are normally distributed with a mean of 265 hours and a standard deviation ó of 10 hours. Find the number of hours that represent ...

### statistics

A construction zone on Kings Road has a posted speed of 45 kilometers per hour. The speeds of vehicle passing through this construction zone are normally distributed with a mean of 46 kilometers per hour and a standard deviation of 4 kilometers per hour. Find the percentage of...

### statistics

. For patients with a certain disease the amount of certain protein in the blood is normally distributed with a mean of 130 and a standard deviation of 5. For patients without the disease the amount of that protein is normally distributed with a mean of 150 and a standard ...

### statistics

For patients with a certain disease the amount of certain protein in the blood is normally distributed with a mean of 130 and a standard deviation of 5. For patients without the disease the amount of that protein is normally distributed with a mean of 150 and a standard ...

### statistics

Can you please tell me how to solve for the following? Pedro took an exam in a class in which the mean was 64 with a standard deviation of 6. If his z score was +3, what was his exam score? A students commute to school is normally distributed with a mean of 31 min and a ...

### Analytical Skills

If your score on a statistics exam was 76 and the professor gave you the distribution for the exam score for your class, you could find your percentile to understand where you stand in comparison to your fellow students. Assume that the distribution for exam scores is normally...

### Statistics

Construct a 99% confidence interval for life expectancy of a new GE light bulb. 64 bulbs are randomly selected and a mean of 750 hours and a standard deviation of 20 hours is found. Assume the distribution of life expectancy is normally distributed.

### Algebra 2

A set of data with a mean of 64 and a standard deviation of 5.9 is normally distributed. What value is within +3 standard deviation of the mean?

### Statistics

find the 90% confidence interval for the variance and standard deviation of the ages of seniors at Oak Park College if a sample of 24 students has a standard deviation of 2.3 years. Assume the variable is normally distributed. Can someone explain the steps to solve this? ...

### Statistics

Given that x is a normally distributed random variable with a mean of 28 and a standard deviation of 7, find the following probability: P(x<28) I understand that the means is 28 and the standard deviation is 7. However what I don't understand is how to get the value of x. ...

### Math

This is my sample: 29,083 ; 25,314, 31,920 ; 30,750 ; 32,302 I need to find the mean and standard deviation of this sample?! How can i assure the life spans are normally distributed?

### college

Assume that the life expectancy of U.S. males is normally distributed with a mean of 80 years and a standard deviation of 4 years. What is the probability that a randomly selected male will live more than 85 years?

### Statistics

An electrical firm which manufactures a certain type of bulb wants to estimate its mean life. Assuming that the life of the light bulb is normally distributed and that the standard deviation is known to be 40 hours, how many bulbs should be tested so that we can be 90 percent ...

### Statistics

Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The results showed that the average tread life was 52,515 miles with a standard deviation of 3,550 miles. What is the best estimate of the average tread life in miles for the ...

### math

The life span of a DVD player produced by one major company is known to be normally distributed with a mean of 6.2 years. If 4.01% of these DVD players have a life span of more than 8 years, what is the standard deviation of the DVD player’s life span?

### Algebra

Mr. Smith has 100 students in his Algebra classes. The grades of a quiz are normally distributed with a mean of 70 and a standard deviation of 4. Sally claims that 75 students scored between 66 and 74 on this quiz. Given that this is normally distributed, is Sally correct?

### math

the battery lifetime is normally distributed for large samples with a standard deviation of 70 days. if 16% of the batteries have a lifetime of 850 or higher, what is the average battery life?

### math

if the life in years of a washing machine is normally distributed with a mean of 15 years and a standard deviation of 1.6 years what should be the guarantee period if the company wants less than 1% of the machines to fail while under warranty

### Statistics

Are these statements true or false? 1. The sample mean, the sample proportion and the sample standard deviation are all unbiased estimators of the corresponding population parameters. 2. If the population is normally distributed with known variance then the sample mean may not...

### statistic

Two samples each of size 25 are taken from independent populations assumed to be normally distributed with equal variances. The first sample has a mean of 35.5 and standard deviation of 3.0 while the second sample has a mean of 33.0 and standard deviation of 4.0. The pooled (i...

### Math

Random variables X and Y are both normally distributed with mean 100 and standard deviation 4. It is known that random variable X+Y is also a normal distribution. a. What is the mean of X+Y? b. What is the standard deviation of X+Y? I see that the mean is 200 but I don't know ...

### algebra

Mr. Smith has 100 students in his Algebra classes. The grades of a quiz are normally distributed with a mean of 70 and a standard deviation of 4. Sally claims that 75 students scored between 66 and 74 on this quiz. Given that this is normally distributed, is Sally correct? ...

### algebra

Mr. Smith has 100 students in his Algebra classes. The grades of a quiz are normally distributed with a mean of 70 and a standard deviation of 4. Sally claims that 75 students scored between 66 and 74 on this quiz. Given that this is normally distributed, is Sally correct? ...

### math

2. Manufacturer A produces hammers that are normally distributed with a mean weight of 4.6 lb and a standard deviation of 0.8 lb. Manufacturer B produces hammers that are normally distributed with a mean weight of 6.3 lb and a standard deviation of 1.4 lb. (a) What percentage ...

### math

Mr. Smith has 100 students in his Algebra classes. The grades of a quiz are normally distributed with a mean of 70 and a standard deviation of 4. Sally claims that 75 students scored between 66 and 74 on this quiz. Given that this is normally distributed, is Sally correct? ...

### Statisitcs

The mean height of fully grown birch trees are 18 feet with a standard deviation of 1.2 feet, normally distributed. Random samples of size 9 are drawn from this population and the mean of each sample is determined. Find that mean and the standard error of the mean, and the ...

### math

A set of data items is normally distributed with a mean of 70. Convert the data item to a z-score, if the standard deviation is as given. data item: 80; standard deviation: 15

### MATH; STANDARD DEVIATION

suppose that prices of a certain model of new homes are normally distributed with a mean of $150,000 use 68-95-99.7 rule to find the percentage of buyers who paid: between $150,000 and $152,000 if the standard deviation is $1200

### statistics

Assume that a population is normally distributed with a mean of 100 and a standard deviation of 15.

### adult education

The lifetimes of lightbulbs of a particular type are normally distributed with a mean of 290 hours and a standard deviation of 6 hours. What percentage of the bulbs have lifetimes that lie within 1 standard deviation to either side of the mean?

### stats

Opisthotrochopodus n sp. is a polychaete worm that inhabits deep sea hydrothermal vents along the Mid-Atlantic Ridge. According to an article by Van Dover et al. in Marine Ecology Progress Series (1999, vol 181 pp 201-214), the lengths of female polychaete worms are normally ...

### Word Problem

A math teacher gives two different tests to measure students' aptitude for math. Scores on the first test are normally distributed with a mean of 25 and a standard deviation of 4.6. Scores on the second test are normally distributed with a mean of 68 and a standard deviation ...

### Statistics

In a survey, the guess at the mean age for the class had a mean of 21.9 and a standard deviation of 3.03. Given that Normally distributed populations have a first quartile of Z=-0.67 and a third quartile of Z=.67, what does this suggest about whether or not these guesses are ...

### math

A medical researcher believes that the standard deviation of the temperatures of newborn infants is greater than 0.6 degrees. A sample of 15 infants was found to have a standard deviation of 0.8 degrees. At the 0.10 level of significance, does the evidence support the ...

### statistics

Assuming that the data are normally distributed with a mean of 45 and a standard deviation of 3.25, what is the z-score for a value of 40?

### Math

X is a normally distributed random variable with a mean of 8.00. If the probability that X is less than 9.54 is 0.67, then what is the standard deviation of X?

### statistics

The life span of the battery pack is known to be Normally distributed with a mean of 250 hours and a standard deviation of 20 hours. How to find the percentage of the battery packs lasting more than 250 hrs.

### Probability & Statistics

The life expectancy (in hours) of a fluorescent tube is normally distributed with a mean 8000 and a standard deviation 1000. Find the probability that a tube lasts for more than 11000 hours.

### Maths

2a) assume that adult males have footless which are normally distributed with mean 24.6 cm and standard deviation 1.05 cm. Calculate the probability that an adult male has a foot length is greater than 27 cm. My answer - 2 2b) assume adult females have foot lengths which are ...

### Finite Math

If the life in years, of a television set is normally distributed with a mean of 46 years and a standard deviation of 4 years, what should be the guarantee period if the company wants less than 3% of the television sets to fail while under warranty?

### statistics

Use the Standard Normal Distribution table to find the indicated area under the standard normal curve. Q1: Between z = 0 and z = 2.24 A1: 0 = 0.5000 2.24 = 0.9875 0.9875 – 0.5000 = 0.4875 Q2:To the left of z = 1.09 A2: 0.8621 Q3: Between z = -1.15 and z = -0.56 A3: -1.15 = 0...

### Statistics

A random variable X is normally distributed with ì = 60. Convert the value of X to a z-score, if the standard deviation is as given. X = 60; ó = 7 A) 7 B) 1 C) 60/70 D) 0

### Statistics

A random variable X is normally distributed with ì = 60. Convert the value of X to a z-score, if the standard deviation is as given. X = 60; ó = 7 A) 7 B) 1 C) 60/70 D) 0

### Statistics

X is normally distributed with a mean of 250 and a standard deviation of 40. What value of X does only the top 15% exceed?

### statistics

Suppose that is normally distributed with mean 90 and standard deviation 12. What value of does only the top 20% exceed?

### statistics

Assuming that the data are normally distributed with a mean of 45 and a standard deviation of 3.25, what is the z-score for a value of 40? (Points : 6) 1.54 2.38 -1.36 -1.54

### ivy tech

Assuming that the data are normally distributed with a mean of 45 and a standard deviation of 3.25, what is the z-score for a value of 40?

### stats

if x is a normally distributed random variable with amean of 8.00 if the proability for x is less than 9.54 is 0.67, then find the standard deviation of x

### statistics

Given a normally distributed population of values with a mean of 76 and a standard deviation of 10 what is the probability that a value is 71 and 82

### stats

The life of tires manufactured by Omega Tires Inc is believed to be normally distributed with a mean of 110,000 km and a standard deviation of 5,000 km. A random sample of 200 tires is tested . What is the problability of the mean life of this sample being between 109,000 and ...

### statistics

It is well known that the heights of individual American men are normally distributed with mean 70 inches and standard deviation 2.8 inches. The Central Limit Theorem states that if n men are randomly chosen, then their average height will also be normally distributed with ...

### math(pls help me)

1.The management committee of Zenith has indicated its desire to accept only 40% of all continuing undergraduate based on the results of the end-of-second semester examinations.the mean score of the examination is 500 and standard deviation of 100.Find the cut off score for ...

### stat

for randomly selected adults, IQ scores are normally distributed with a standard deviation of 15. the scores of 14 randomly selected college students are listed below. use a 0.10 significance level to test the claim that the standard deviation of IQ scores of college students ...

### statistics

The lifetimes of light bulbs of a particular type are normally distributed with a mean of 370 hours and a standard deviation of 5 hours. What percentage of bulbs has lifetimes that lie within 1 standard deviation of the mean on either side?

### math

2) The lifetimes of light bulbs of a particular type are normally distributed with a mean of 370 hours and a standard deviation of 5 hours. What percentage of bulbs has lifetimes that lie within 1 standard deviation of the mean on either side?

### stats

Assume that aset of test scores is normally distributed with a mean of 100 and a standard deviation of 20 use the 68-95-99?

### statistics

the random variable x is normally distributed with a mean of 75 and a standard deviation of 15.0. For this distribution, what is the twenty-third percentile?

### statistics

Scores on an english test are normally distributed with a mean of 33.6 and a standard deviation of 8.3. Find the 41st percentile?

### Math

Random variable X is normally distributed with mean 10 and standard deviation 2. Compute the following probabilities. a. Pr(X<10) b. Pr(X<11.04) I don't know where to start.

### MATH

At one college, GPA’s are normally distributed with a mean of 2.9 and a standard deviation of 0.6. Find the 70th percentile.

### Statistics

At one college, GPA’s are normally distributed with a mean of 2.9 and a standard deviation of 0.6. Find the 70th percentile.

### statistics

The most common intelligence quotient (IQ) scale is normally distributed with mean 100 and standard deviation 15. What score would put a child 3 standard deviations above the mean

### statistics

The most common intelligence quotient (IQ) scale is normally distributed with mean 100 and standard deviation 15. What score would put a child 3 standard deviations above the mean

### statistics

IQ scores distribution of IQ scores is not normally distributed standard with a mean of 100 and a standard deviation of 15, which is represented by a bell-shaped graphical. What is the area under the curve? What is the median? What is the mode?

### statistics

IQ scores distribution of IQ scores is normally distributed standard with a mean of 100 and a standard deviation of 15, which is represented by a bell-shaped graphical. What is the area under the curve? What is the median? What is the mode?

### STATISTICS

IQ scores distribution of IQ scores is normally distributed standard with a mean of 100 and a standard deviation of 15, which is represented by a bell-shaped graphical. What is the area under the curve? What is the median? What is the mode?

### college math

Math homework please help!! 2. Suppose that people’s weights are normally distributed, with mean 175 pounds and a standard deviation of 6 pounds. Round to the nearest hundredth of a percent a. What percent of the population would weigh between 165 and 170 pounds? b. What ...

### Stats

Suppose the time it takes for a purchasing agent to complete an online ordering process is normally distributed with a mean of 8 minutes and a standard deviation of 2 minutes. Suppose a random sample of 25 ordering processes is selected. The standard deviation of the sampling ...

### statistics

The numbers of hours of life of a torch battery is normally distributed with a mean of 150 hours and standard deviation of 12 hours. In a quality control test, two batteries are chosen at random from a batch. If both batteries have a life less than 120 hours, the batch is ...

### sTATISTICS

If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, approximately what percentage of light bulbs has a life of more than 3000 hours?

### statistics

IQ scores are normally distributed with a mean of 105 and a standard deviation of 18. Assume that many samples of size n are taken form a large population of people and the mean IQ score is computed for each sample. If the sample size is n=64, find the mean and standard ...

### statistics

the dean of admissions in a large university has determined that the scores of the freshman class in a mathematics test are normally distributed with a mean of 86 and a standard deviation of 11. A sample of 50 students is selected at random from the entire freshman class. ...

### statistics

if the mean of a normally distributed set of data is 100 and the standard deviation is 10, a z score of 2 corresponds to raw value of?

### statistics

A population is normally distributed with a man of 100 and a standard deviation of 15. is it unusual for themean of a sample of 3 to be 115 or more? Why or why not?

### statistics

Scores on an English test are Normally distributed with a mean of 78% and a standard deviation of 4.5%. Find the Value of the first quartile.

### statistics

skating speeds are normally distributed with a mean of 60 and a standard deviation of 10. Determine the speed that separates the top 6% from the rest.

### language arts HELP PLZ!!!!!!!

what is the purpose of the bracketed information in the intro? [old english tread to tread] A.it gives an alternate pronunction of tread B.it gives the origin of tread C.it gives an alternate spelling of tread D.it gives a synonym of tread

### statistics

Cholesterol levels of adult males are approximately normally distributed with a mean of mg/dL and a listed standard deviation of . Some researchers claim that the standard deviation of cholesterol levels of adult males is less than . Suppose that we want to carry out a ...

### statistics

An investment broker reports that the yearly returns on common stocks are approximately normally distributed with a mean return of 12.4 percent and a standard deviation of 20.6 percent. On the other hand, the firm reports that the yearly returns on tax-free municipal bonds are...

### algebra 2

The time it takes for climbers to reach the highest point of a mountain is normally distributed with a standard deviation of 0.75 hours. If a sample of 35 people is drawn randomly from the population, what would be the standard error of the mean of the sample?

### math

kris scored 630 points on a particular section of a CPA exam for which the score were normally distributed with a mean of 600 points and a standard deviation of 75 points. At a differenttime, kerry scored 540 points on the same section, for which scores were normally ...

### math

kris scored 630 points on a particular section of a CPA exam for which the score were normally distributed with a mean of 600 points and a standard deviation of 75 points. At a differenttime, kerry scored 540 points on the same section, for which scores were normally ...

### finite math

kris scored 630 points on a particular section of a CPA exam for which the score were normally distributed with a mean of 600 points and a standard deviation of 75 points. At a differenttime, kerry scored 540 points on the same section, for which scores were normally ...

### sample size/ standard deviations

How do we compute sample size fluctuations? Suppose we have a population of 16000 and a sample size of 30, and the number of samples 1000, what will be the impact on population mean and standard deviation when the population is normally distributed? When the population is ...

### statistics

Let x be a continuous random variable that is normally distributed with a mean of 65 and a standard deviation of 15. Find the probability that x assumes a value less than 44.

### statistics

Let x be a continuous random variable that is normally distributed with a mean of 65 and a standard deviation of 15. Find the probability that x assumes a value less than 45.

### statistics

In a population of normally distributed aptitude scores of 1000 academy students with mean 70 and Standard deviation 10, how many score above 95?