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Normal Distribution

Normal distribution

6.12 a. The area under the standard normal curve with parameters m = 64.4 and o= 2.4 that lies to the left of 61 is 0.0783. Use this information to estimate the percentage of female's students who are shorter than 61 inches. 6.14 According to the National Health and Nutrition Examination Survey, the serum (noncellular portio

Using Excel to make plots of Gaussian distribution

I am using Analytical Chemistry 7th edition By Skoog, West, Holler, and Crouch. please let me know if any additional info. is needed. There is a sample of the graph in the book Chapter 6 and 7. Using Excel, construct a spreadsheet to make two plots of a Gaussian distribution: 1. relative frequency vs deviation from the mean

Normal Distribution; Mean; Standard Deviation Functions

I am having trouble with PART B of this problem. Here is the whole problem: Assume body temperatures are normally distributed with mean of 98.2 and a standard dev. of 0.62 Part A) Assuming a hospital defines a fever as 100 or over, determine the percentage of a normal healthy person considered to have a fever using Z tabl


Question 1 If a normal distribution of empirical scores is converted to a distribution of z scores: A. The new mean will be zero B. The new standard deviation will be one C. Both A and B D. Neither A and B. Question 2 Milquetoasts gracious statistics professor at Northwestern announced that he would drop th

Finding percentiles of known normal distributions

All standard IQ test scores are normally distributed and are set up so that the mean score is 100. However, the standard deviation differs from test to test. For example, the standard deviation on the Otis-Lennon test is 16, while the Cattell's standard deviation is 24. The following are three famous high IQ societies, with t

Find the Critical Values and Determine the Appropriate Distribution

Do one of the following as appropriate: a) Find the critical value t (alpha/2) b) Find the critical value z (alpha/2) c) State that neither the normal nor the t distribution applies. Problem: 95%; n= 40; sigma is unknown; population appears to be skewed. (See attachment for complete question and symbols that did not come

Distribution Function Requirements

How do I know which distribution to use for the following and when/where do tables apply?: Nonstandard Normal Binomial Normal Standard normal Central limit theorem a) Mean is 0, stand. dev. is 0 degrees C., find P between 0.05 and 1.50 b)Mean is 63.6 and s.d. is 2.5; Club had requirement that women must be 70 inches

Random Sample Population Variance

A. n=17. Find P(t<-1.746) aa) .05 bb).95 cc).45 dd) 1.0 B. A random sample of 64 observations is observed from a population of SAT scores in 2001. Which of the following is a correct statement? aa) It is the distribution of the observed 64 SAT scores. bb) X-bar is approximately normal. cc) The mean of all possible x-bars is ave

Only for 103997

Only for above listed OTA. Last one for this semester. Thank you. Hope you're around mid- June through July. Have a great summer! Problem: In a stan. normal distribution, find the z-score that separates the top 20% area from the bottom 80%.

Estimated percentile rank

Tthe mean for a special distribution is 100 and the standard deviation is 15. What is the estimated percentile for an individual who had a score of 90 on this scale?

Questions from Textbook: Statistics for Management (7th Ed. ) Levin & Rubin

1). In a normal distribution with a standard deviation of 5.0, the probability that an observation selected at random exceeds 21 is 0.14 (14%). a). Find the mean of the distribution. b). Find the value of below which 4 percent of the values in the distribution lie. 2). The company's manager calculates that it requires

Normally dist with mean and SD

Nurses saleries are Normally distributed with mean of 35,000 and standard deviation$1700. A. What is the probability that a nurse earn more than $36,000? B. What is the probality that a group of 10 nurses have mean salary greater than $36,000? c. What salary does a nurse need to earn to have a salary in the top 25% of nurses'

Distribution Elementary Statistics

I need some serious explanation. I cannot even understand what to study for the frist 6 questions on the test about the formula I posted in this subject line. The book I am using is Elementary Statistics by mario F. Triola. 8th edition. Here is what I am to study: Students will have 2 hours to answer 20 exam questions.

Normal Distribution problem

The amounts dispensed by a cola machine follow the normal distribution with a mean of 7 ounces and a standard deviation of 0.10 ounces per cup. How much cola is dispensed in the largest 1 percent of the cups?

Hypothesis in statistics

A light bulb manufacturer advertises that the average life for their light bulbs is 800 hours. A random sample of 15 of their light bulbs resulted in the following data, in hours; 990 841 953 612 727 800 686 594 835 897 943 791 750 667 723 Assume that the bulb life is normally distributed. At the 10% significance level, do

Estimation using Normal Distribution

A random sample of 55 adults in a certain country showed an average height of six feet (72 inches) for adults. Statistics show the population standard deviation to be 3.40 inches. Calculate the 95% confidence interval for the mean height of the adult population.

What inventory levels to carry? Simulation? Optimization?

We are asked (ideally) to use Crystal Ball (CB), an Excel add-in, or Excel itself to do this inventory problem. CB would be ideal, but we can use just plain-old Excel if it can do what needs to be done. I see this as a simulation or maybe optimization problem, but not sure how to tackle it. Given historical data on deman

Probability Distributions: Normal Distribution

It is known that the IQ scores of workers in a certain company are normally distributed with a standard deviation of ten. If 0.13% of the workers have IQ's in excess of 130 calculate the mean IQ.

Probability Distributions: Normal Distribution

According to the census, the average age of men marrying for the first time is 24 years. Assume ages of men are normally distributed with a standard deviation of three years. A) What is the probability that a man being married for the first time is older than 26 years? B) Before what age do 95% of men who marry for the first t

Probability Distributions: Normal Distribution

Foreign service employees receive housing allowances when posted abroad. These allowances average $30000 annually. Assume that a normal distribution applies and the standard deviation is $5000. A) What is the probability that a diplomat will receive a housing allowance exceeding $35000? B) What is the probability that a diplom

Normal (z) Distributions- In grading Oranges into "A","B" and "C", a large orchard uses weights to distinguish Oranges. If the day's pick shows 16.6% are grade "A" and 6.68% are grade "C", determine the Mean and Standard Deviation.

In grading Oranges into "A","B" and "C", a large orchard uses weights to distinguish Oranges. Any Orange weighing more than 2 ounces is classified as grade "A", while an Orange weighing less than 0.75 ounces is classified as grade "C". If the day's pick shows 16.6% are grade "A" and 6.68% are grade "C", determine the Mean and St

Acceptance-sampling scheme

Consider an acceptance-sampling scheme in which a factory takes delivery of a batch of components if a random sample of 400 components contains fewer than M defectives. Otherwise the batch is returned tot he supplier. Suppose the factory manager wants to set M so that there is no more than a 10% risk of accepting a batch that

Mean and variance

7) suppose the average weight of an item labeled 16 ounces actually has mean 17 ounces and variance 4 (ounce^2). What is the approximate probability that the combined weight of 25 items exceeds 445 ounces? What theorem is useful in answering this question?

Normal distribution

A very large number of fish are swimming in a lake. Their weights are normally distributed with mean 1.30kg and a standard deviation 0.40kg. Fish caught with weights less than 0.5kg have to be thrown back. a) If an angler catches a randomly selected fish, what is the probability that the fish has to be thrown back? b) find

Normal distribution

A university professor keeps records of his travel time while he is driving between his home and the university. Over a long period of time he has found that his morning travel times are approx Normally distributed with a mean of 31 minutes and a standard deviation of 3.0 minutes;his return journey in the evening is similarly d

Joint Distributions (normal distributions)

Tim has two more problems to solve on his test, but he doesn't know how long it will take to finish them. He assigns mutually irrelevant normal distributions to the times, assigning a mean of 35 minutes to the first problem and 30 minutes to the second problem. He assigns a 95% chance that the first problem will take 35+-15 minu

Normal distribution and percentiles

True or false: It is not possible for the score in a distribution, not necessarily normal, which ranks as the 90th percentile to also be the mode for the distribution.

Normal Distribution

In a production run of 40 of a particular model of radiation detector, there are four which have defective circuits. If a sample of three of these is chosen without replacement, what is the probability that all three will be defective?

Normal distribution, standard deviation and mean

True or false: When the variable is normally distributed, the sample size is less than 30, and the population standard deviation is known, then the t distribution must be used to find confidence intervals for the mean.