# standard deviation

10,100 results

statistics
worried about customer complaints and potential lawsuits, the manufacterers decided that no more than o.5% of bags of Crunchy corn chips should be underweight. there are 2 possible adjustments that can be made; change the mean setting on the filling machines while leaving the ...

statistics
If the mean I.Q. is 100 and the standard deviation of I.Q. scores is 15, then an I.Q. of 130 will have a z score (or standard score) of?

Statistic
Twenty students assigned to an experimental group receive 30 in a control group has a mean of 38 on the test (with an estimated population standard deviation of 3); the control group has a mean of 35 (with an estimated population standard deviation of 5). Using the .05 level, ...

Psychology
Twenty students randomly assigned to an experimental group receive an instructional program; 30 in a control group do not. After 6 months, both groups are tested on their knowledge. The experimental group has a mean of 38 on the test (with an estimated population standard ...

Statistics
A study was conducted to investigate relationships between different types of standard test scores. On the Graduate Record Examination verbal test, 18 women had a mean of 538.82 and a standard deviation of 114.16, and 12 men had a mean of 525.23 and a standard deviation of 97....

QNT
A sample of 100 students participate in a final exam. The mean score is 88 with a standard deviation of five (5). What is the standard error of the measurement of the mean?

Statistics
The t distribution should be used when ___. the sampling population is not normal the sampling population is unimodal The sampling distribution is normal and the population standard deviation is unknown the population standard deviation is known

Math- Assignment Due
Please help me, it would be greatly appreciated. 1.) A set of data was collected as shown in the table. Data value: Frequency: 5. 9 6. 9 7. 14 8. 9 9. 13 10. 7 11. 9 The standard deviation of the data is A..) 1.90 B.) 2.00 C.) 2.33 D.) 7.93 2.) A group of apples from a ...

Statistics
Among employed women, 25% have never been married. Select 10 employed women at random. What is the mean number of women in such a sample who have never been married? What is the standard deviation? I think the mean would be 2.5, but I'm not sure about the standard deviation.

****HELP**** STATISTIC
The table below shows the probability distribution of the types of food purchased by students from the school cafeteria. What is the probability a student has purchased Caesar salad? (2 points) 0.17 Suppose houses are available for purchase during construction of a new housing...

7. The table below shows the probability distribution of the types of food purchased by students from the school cafeteria. What is the probability a student has purchased Caesar salad? (2 points) 0.17 Suppose houses are available for purchase during construction of a new ...

12
A factory’s worker productivity is normally distributed. One worker (worker 1) produces an average of 75 units per day with a standard deviation of 20. Another worker (worker 2) produces at an average rate of 65 per day with a standard deviation of 21. What is the ...

maths help
What is the least number of rolls should a fair standard 6-sided die be done so that the recorded numbers that have been shown approximates a binomial distribution of standard deviation of 10 and a success occurs when a 4 is tossed?

Probability and Statistics
A research psychologist believes that professional athletes tend to be more confident than the typical person. From previous testing, he knows that the scores for people in the general population are approximately normally distributed with a mean of 72 and standard deviation ...

math
One of the tallest living men has a height of 263 cm. One of the tallest living women is 245 cm tall. Heights of men have a mean of 177 cm and a standard deviation of 8 cm. Heights of women have a mean of 163 cm and a standard deviation of 4 cm. Relative to the population of ...

Statistics
Two high school students took equivalent language tests, one in German and one in French. The student taking the German test, for which the mean was 66 and the standard deviation was 8, scored an 82, while the student taking the French test, for which the mean was 27 and the ...

If a population has a standard deviation σ of 18.2 units, what is the standard error of the mean if samples of size 25 are selected? Show all work. standard error of the mean = 0/sqrt(n) = 18.2/sqrt(25) = 18.2/5 =3.64 Answer 3.64

statistics
If someone scored two Standard Deviations above the Mean on a standardized test where the Mean = 100 and the Standard Deviation = 15, then that person’s numerical score would be…?

statistics
What would a person's numerical score be if someone scored two Standard Deviations above the Mean on a standardized test where the Mean = 100 and the Standard Deviation =15?

Maths
10 marks add to each of the 12th standard students marks due to poor result which of the following measure does not change? (A)mean (b) median (c) mode(d) standard deviation

statistics
7. A sample of 40 observations is selected from one population. The sample mean is 102 and the sample standard deviation is 5. A sample of 50 observations is selected from a second population. The sample mean is 99 and the sample standard deviation is 6. Conduct the following ...

Statistics
8. A sample of 65 observations is selected from one population. The sample mean is 2.67 and the sample standard deviation is .75. A sample of 50 observations is selected from a second population. The sample mean is 2.59 and the sample standard deviation is .66. Conduct the ...

Estimating Using Confidence Intervals
An investor wants to determine the true average yield on a selection of investments from the Business week 1000. Suppose the investor draws a random sample of (n=40 firms) and finds an average yield on investment of (xbar = 5.00%) and a sample standard deviation (s = 1.50%). ...

Stor 155
Use the definition of the mean to show the sum of the deviation of the observations from their mean is always zero. This is one reason why variance and standard deviation use squared deviations.

statistics
A sample of 12 measurements has a mean of 34 and a standard deviation of 4.5. Suppose that the sample is enlarged to 14 measurements, by including two additional measurements having a common value of 34 each. A. Find the mean of the sample of 14 measurements. Mean = B. Find ...

1.  Suppose that the mean of the annual return for common stocks from 1950 to 2012 was 9.4%, and the standard deviation of the annual return was 17.5%.  Suppose also that during the same 62-year time span, the mean of the annual return for long-term government bonds was 4.6...

STATISTICS
Standard error: Is always the standard deviation divided by the square root of n. Is a measure of the variability of a sample statistic. Increases with bigger sample sizes. All of the above.

statistics
Scores on a national writing exam are approximately normally distributed, with a mean of 490 and a standard deviation of 20. Consider random samples of size 25 from the population of test takers. describe the sampling distribution of a sample mean. shape mean= standard ...

SMU
A sample of 25 concession stand purchases at the October 22 matinee of Bride of Chucky showed a mean purchase of \$5.29 with a standard deviation of \$3.02. For the October 26 evening showing of the same movie, for a sample of 25 purchases the mean was \$5.12 with a standard ...

statistics
using the numbers only 0 through 10 only whole numbers with repeats allowed pick four numbers that would have the smallest standard deviation I said four zeros pick four numbers that would have the largest standard deviation I said 0 0 0 10 is there more than one correct ...

statistics
hi, how would i calculate the standard deviation of the following sampling distribution of means. apparently this is the longhanded way of calculating standard error. *a population of scores contains exactly 5 scores : 2, 3, 6, 8, 11 (2, 2) ... 2 (2, 3) ... 2.5 (2, 6) ... 4 (2...

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

Stats
A large population has a mean of 200 and a standard deviation of 40. Which one of the following best describes the percentage of measurements that fall in an interval that is within two standard deviations of 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?

statistics
A factory's worker productivity is normally distributed. One worker produces an average of 72 units per day with a standard deviation of 23. Another worker produces at an average rate of 68 units per day with a standard deviation of 23. A. What is the probability that in a ...

statistic
The mean salary per day of all the 5000 employees who work in a company is 150 Rs. and the standard deviation is 15 Rs. Let be x bar is the mean salary per day for a random sample of certain employees selected from this company. Find the mean and standard deviation for sample ...

Math-confused...plz help
I. Use Chebyshev’s theorem to find what percent of the values will fall between 183 and 227 for a data set with a mean of 205 and standard deviation of 11. II. Use the Empirical Rule to find what two values 99.7% of the data will fall between for a data set with a mean of ...

Math
Susan owns a chocolate store. She sells her chocolate by the gram and needs to compare the weights of two chocolate batches. She randomly selects 100 pieces from each batch. The distrubition of both samples are normal. Batch 1 - (Mean Weight) 56 grams Standard Deviation - 6 ...

statistics
Please read and use the following information to answer questions 11, 12, and 13: Big packages of M&M Plain Candies have a mean weight of 16 ounces with a standard deviation of .15 ounces. A chocolate loving researcher decides to a random sample of 20 big bags of M&M Plain ...

prob. & stat
In a random sample of 63 women at a company, the mean salary is \$48,902 with a standard deviation of \$5270. In a random sample of 50 men at the company, the mean salary is \$53,454 with a standard deviation of \$4677. Construct a 95% confidence interval for the difference ...

prob & stat
In a random sample of 63 women at a company, the mean salary is \$48,902 with a standard deviation of \$5270. In a random sample of 50 men at the company, the mean salary is \$53,454 with a standard deviation of \$4677. Construct a 95% confidence interval for the difference ...

statistics
A sample of 25 concession stand purchases at the October 22 matinee of Bride of Chucky showed a mean purchase of \$5.29 with a standard deviation of \$3.02. For the October 26 evening showing of the same movie, for a sample of 25 purchases the mean was \$5.12 with a standard ...

statistics
ok i was given a set of data asked to create a graph of my choice to represent the data then i'm asked Does the sahpe of the distribution allow the use of the mean and the standard deviation to describe it? ok how does the mean and the standard deviation effect the shape of ...

Math-Statistics
I. Use Chebyshev’s theorem to find what percent of the values will fall between 156 and 276 for a data set with a mean of 216 and standard deviation of 12. II. Use the Empirical Rule to find what two values 68% of the data will fall between for a data set with a mean of 219 ...

From the length(in seconds) of 80 randomly chosen U2 songs, the mean determined was 289.6986295 and standard deviation was 76.82292002. Assume that the data is normally distributed and that the bands entire collection of songs has a mean and standard deviation equal to those ...

Algebra
On a standardized test, the distribution of scores is normal, the mean of the scores is 75, and the standard deviation is 5.8. If a student scored 83, the student's score ranks 1. below the 75th percentile 2. above the 97th percentile 3. between the 75th percentile and the ...

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 ...

math (statistics
John's z-score on a college entrace exam is 1.3. If the raw scores have a mean of 480 and a standard deviation of 70 points, what is his raw score? Use a z-score formula to find John's raw score. The formula: z = (x - mean)/sd -->sd = standard deviation Using what you know ...

Math
I. Use Chebyshev’s theorem to find what percent of the values will fall between 156 and 276 for a data set with a mean of 216 and standard deviation of 12. II. Use the Empirical Rule to find what two values 68% of the data will fall between for a data set with a mean of 219 ...

Stats
I. Use Chebyshev’s theorem to find what percent of the values will fall between 183 and 227 for a data set with a mean of 205 and standard deviation of 11. II. Use the Empirical Rule to find what two values 99.7% of the data will fall between for a data set with a mean of ...

statistics
Question: A standard placement test has a mean of 105 and a standard deviation of ó = 13. Determine the minimum sample size if we want to be 99% certain that we are within 3 points of the true mean. Answer: N = ( zc ó/E)^2 = (2.575 x 13/3)^2 = 121

Math Statistics
I am confused I want to find the values of the equation of Yi=a + bxi. Time spent on twitter is the predictor variable and time spent working on twitter is the response The correlation between minutes spent on twitter and minutes spent working is -0.5 The standard deviation in...

Statistics
Suppose the heights of 18-year-old men are approximately normally distributed, with mean 66 inches and standard deviation 4 inches. (a) What is the probability that an 18-year-old man selected at random is between 65 and 67 inches tall? (Round your answer to four decimal ...

Algebra
A supervisor finds the mean number of miles that the employees in a 9the x has a line on top)department live from work. He finds X=2.9 and s=3. Which statement must be true? z376 is within 1 standard deviation of the mean. z37 is between 1 and 2 standard deviations of the mean...

finance
The expected return on the market is 12% and the risk free rate is 7%. The standard deviation of the return on the market is 15%. Ones investor creates a portfolio on the efficient frontier with an expected return of 10%. Another creates a portfolio on the efficient frontier ...

statistics
The mean number of fitness magazines in a sample of homes is 16, the standard deviation is 5; and the mean for the number of pages of fitness magazines in a sample of homes is 43, with a standard deviation of 8. Which set of data set is more variable?

statistics
The average amount spent at a fast-food restaurant in California was \$3.30, with a standard deviation of \$.40. Yet in Georgia, the average amount spent at a fast-food restaurant was \$3.25, with a standard deviation of \$.10. What do these statistics tell you about fast-food ...

Statistics
Data from the latest census was analyzed. It was determined that one-parent households spend less on food away from home that do two-parent households. The mean amount spent by 30 one-parent households is \$1876 and the standard deviation is \$113. The mean amount spent by 30 ...

Consider the following set of data. (25, 6), (25, 51), (62, 34), (84, 15), (112, 57), (122, 14) (a) Calculate the covariance of the set of data. (Give your answer correct to two decimal places.) 40.17 (b) Calculate the standard deviation of the six x-values and the standard ...

math
A sample of 145 values is randomly selected from a population with mean, ì, equal to 45 and standard deviation, ó, equal to 23. (Give your answers correct to one decimal place.) (a) Determine the interval (smallest value to largest value) within which you would expect 99.7% ...

stats
One company produces movie trailers with mean 150 seconds and standard deviation 40 seconds, while a second company produces movie trailers with mean 120 seconds and standard deviation 30 seconds. What is the probability that two randomly selected trailers, one produced by ...

statistics
Data from the latest census was analyzed. It was determined that one-parent households spend less on food away from home that do two-parent households. The mean amount spent by 30 one-parent households is \$1876 and the standard deviation is \$113. The mean amount spent by 30 ...

statistics
Jack’s ACT score is 30. Jason’s SAT score is 950. Who did better? The mean SAT score is 1000 with a standard deviation of 100 SAT points. The mean ACT score is 22 with a standard deviation of 3 ACT points

Statistic
Twenty students assigned to an experimental group receive 30 in a control group has a mean of 38 on the test (with an estimated population standard deviation of 3); the control group has a mean of 35 (with an estimated population standard deviation of 5). Using the .05 level, ...

Statistics
Assume there are two lakes containing trout and the weights of the trout in each lake are normally distributed. The distribution of trout weight in Lake A has a mean of 18 ounces with a standard deviation of 2 ounces. The distribution of trout weight in Lake B has a mean of 19...

statistics
A study found that citizens spend on average \$1950 per year on groceries with a standard deviation of \$100. Assume that the variable is normally distributed. 5. Identify the population mean. 6. Identify the population standard deviation. 7. Find the probability that a sample ...

Sampling Distribution
Sampling Distribution Complete solutions and illustrations are required. 5.The standard deviation of a variable is 15. If a sample of 100 individuals are selected compute for a.The standard error of the mean. b.What sample size is necessary to double the standard error of the ...

English
I am psueo conducting an experiment on 144 freshmen high school students who are evenly divided into 6 groups. The treatment group are receiving a new instructional strategy that the control group is not receiving. A t-test was conducted after a pre-test of a CBM measurement, ...

Stats
The amount of time Ricardo spends brushing his teeth follows a Normal Distribution with unknown mean and standard deviation. Ricardo spends less than one minute brushing his teeth about 40% of the time. He spends more than two minutes brushing his teeth 2% of the time. Use ...

Math
A friend claims that the average length of trout caught in this lake is 19 inches. To test this claim we find that a sample of 13 trout has a mean length of 18.1 inches with a sample standard deviation of 3.3 inches. The population standard deviation is unknown. If you assume ...

A sample of 40 investment customers serviced by an account manager are found to have had an average of \$23,000 in transactions during the past year, with a standard deviation of \$8500. A sample of 30 customers serviced by another account manger averaged \$28,000 in transaction...

Statistics
What is the mean and standard deviation of 63.7%? What is the mean and standard deviation of 61.4%? Using the 68-95-99.7 rule, describe the sampling distribution of 63.7% Using the 68-95-99.7 rule, describe the sampling distribution of 61.4%? Please help I am so lost...

Statistics
What is the mean and standard deviation of 63.7%? What is the mean and standard deviation of 61.4%? Using the 68-95-99.7 rule, describe the sampling distribution of 63.7% Using the 68-95-99.7 rule, describe the sampling distribution of 61.4%? Please help I am so lost...

psy
Eric has computed that it takes an average (mean) of 17 minutes with a standard deviation of 3 minutes to drive from home, park the car, and walk to his job. One day it took Eric 21 minutes to get to work. You would use the formula for transforming a raw score in a sample into...

statistics
f someone scored two Standard Deviations above the Mean on a standardized test where the Mean = 100 and the Standard Deviation = 15, then that person’s numerical score would be…? A. 125 B. 130 C. 160 D. 90th Percentile

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?

Statistics
A driving machine was employed to hit a sample of 41 each of two different brands of golf balls using the same force each time. The research team measured the distance between the point of impact and where the ball eventually came to rest on the ground. Results are show below...

probs & stats
A teacher gives 200 students a study guide for a test and the average score was 90 with a standard deviation of 6. She did not give the other 200 students a study guide and their average score was 70 with a standard deviation of 8. Find the critical value to determine whether ...

statistics
I.use the chebyshev's theorem to find out what percentage of the values will fall between 201 and 257 for a data set with a mean of 229 and standard deviation of 14. II. use the emperical rule to find out two values 68% of the data will fall between for a data set with a mean ...

Math
On a test whose distribution is approximately normal with a mean of 50 and a standard deviation of 10, the results for three students were reported as follows: Student Opie has a T-score of 60. Student Paul has a z-score of -1.00. Student Quincy has a z-score of +2.00. Obtain ...

Stasistic
On a test whose distribution is approximately normal with a mean of 50 and a standard deviation of 10, the results for three students were reported as follows: Student Opie has a T-score of 60. Student Paul has a z-score of -1.00. Student Quincy has a z-score of +2.00. Obtain ...

Statistics
I took a large sample of households in a city, and based on that, estimate the standard deviation of the income for all households in the city is \$800. In order to make a desired conclusion about the income for all the households in the city, I want the sample mean for another...

Statistics and Probability
I took a large sample of households in a city, and based on that, estimate the standard deviation of the income for all households in the city is \$800. In order to make a desired conclusion about the income for all the households in the city, I want the sample mean for another...

fiance
Sonny owns \$5,000 worth of High Risk Enterprises (HRE) stock. HRE has a standard deviation of 16 percent and a beta of 2.0. He wants to invest another \$5,000 and create a \$10,000 portfolio that is equally as risky as the overall market. Which one of the following will ...

Math
Sonny owns \$5,000 worth of High Risk Enterprises (HRE) stock. HRE has a standard deviation of 16 percent and a beta of 2.0. He wants to invest another \$5,000 and create a \$10,000 portfolio that is equally as risky as the overall market. Which one of the following will ...

Investing
Sonny owns \$5,000 worth of High Risk Enterprises (HRE) stock. HRE has a standard deviation of 16 percent and a beta of 2.0. He wants to invest another \$5,000 and create a \$10,000 portfolio that is equally as risky as the overall market. Which one of the following will ...

statistics
2. Why is it important to know the mean and standard deviation for a data set when applying the empirical rule? 3. If we are focused on 68% of the normal distribution, what percentage of the distribution is left in the upper tail only? 4. What value separates the 50% of the ...

Statistics
A normal population has an expected value of 60 and a variance of 30. Use the central limit theorem to determine what the sample size should be such that the mean has a probability of 90% to fall between the values 58 and 62. One concept of the Central Limit Theorem is ...

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
10. A teacher gives 200 students a study guide for a test and the average score was 90 with a standard deviation of 6. She did not give the other 200 students a study guide and their average score was 70 with a standard deviation of 8. Find the critical value to determine ...

Statistics
10. A teacher gives 200 students a study guide for a test and the average score was 90 with a standard deviation of 6. She did not give the other 200 students a study guide and their average score was 70 with a standard deviation of 8. Find the critical value to determine ...

Statistics
A school psychologist decided to separate some classes by gender to see if learning improved. She looked at studded scores on the final exam and obtained the following information: Students in boy-girl classrooms obtained an average of 71.4 on their final exams with a standard...

statistics
What is the formula to do this exercise, Please. A sample of 40 investment customers serviced by an account manager are found to have had an average of \$23,000 in transactions during the past year, with a standard deviation of \$8500. A sample of 30 customers serviced by ...

statistics
1. A random sample of 100 computers showed a mean of 115 gigabytes used with a standard deviation of 20 gigabytes. What is the standard error of the mean?

algebra
On his midterm exam, Jimmy scored 75 points, which was exactly 2 standard deviations above the mean. If the standard deviation for the test is 4, what is the mean for the test?

statistics
The distribution score for a city wide math test scores results in a mean of 70 and a standard deviation of 12. What score is 2 standard deviations above the mean?

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