Statistics Homework Answers & Questions

Waiting for answer What is the empirical rule and how does it differ from Cheby...
The Empirical rule can be used for bell shaped data ONLY. Chebyshev's inequality on the other hand can be used on any data set to find the percentile of a given value or data point....
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Waiting for answer 1.What is x if the mean of the numbers 4,5,x,8,9 and 3 is 6?...
1) ##x = 7##. 2) Median = ##7.5## Explanation: Recall that the arithmetic mean ##bar x## of a data set may be determined as follows: ##bar x = sum_(i=1)^n x_i/n##. where n = number of numbers you adding up and ##x##= the number Thus, for our initial data set: ##6 = (...
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Waiting for answer What is the difference between categorical (qualitative) dat...
Actually there are three main types of data. Qualitative or categorical data have no logical order, and can't be translated into a numerical value. Eye colour is an example, because 'brown' is not higher or lower than 'blue'. Quantitative or numerical data are numbers, and that way they 'impose'...
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Waiting for answer What is the difference between using the pooled variance and...
I have found a nice example for you to check out on the Penn State web page. With the final notice saying: "Comparing two proportions – For proportions there consideration to using "pooled" or "unpooled" is based on the hypothesis: if testing "no difference" between the two proportions then we wi...
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Waiting for answer What is the mode of the numbers: 4, 7, 2, 4, 2, 2, 8, 7, 4,...
Mode is ##2## Mode is the value of the number with highest frequency in the set of datapoints that is the one that occurs most often. To find the mode of numbers ##{4, 7, 2, 4, 2,...
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Waiting for answer What is the importance of descriptive statistics?
Descriptive statistics is important because it enables us to present data in a meaningful way, and therefore allows for a simpler interpretation of the data. Descriptive statistics i...
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Waiting for answer What is the difference between continuous data and discrete...
The main difference is that continuous data are measurable, and discrete data can have only certain values. They may be countable. Examples of continuous :** Height, weight, income are measurable and can have any value. Examples of discrete : Actually there are two kinds of discrete data:Countab...
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Waiting for answer When do you accept or reject the null hypothesis in a chisq...
You have two values: Your ##chi^2 ## test statistic, which is the value you calculated. And, your ##chi^2## critical value. Which is the value you took from the table at a certain degrees of freedom and level of significance. If your TEST STATISTIC exceeds your CRITICAL VALUE, you REJECT the nul...
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Waiting for answer What is the difference between statistical significance and...
is typically defined when the chance of falsely rejecting the null hypothesis is less than 0.05. To put it another way statistical significance occurs when there is less than a 5% chance that the measured result between groups is truly present and not just due to random effects. Practical signific...
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Waiting for answer How do you find the sample standard deviation on a TI84?
Standard deviation can be calculated using several methods on the TI84 C Silver Edition. Standard deviation can be calculated by using the stdDev() function. The stdDev() function can be located by performing the following: • Press [2nd][LIST]. • Scroll to MATH and select 7:stdDev(. Follow the exa...
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Waiting for answer How do you construct a cumulative relative frequency distrib...
Definitionwise cumulative frequency are simply accumulated frequency. Let's have the following definition: Less than cumulative frequency ( Cf) is the number of observations less than the upper class boundary of a class. Greater than cumulative frequency ( Cf) is the number of observations greate...
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Waiting for answer What is the significance of covariance? What does it mean wh...
Covariance is a linear measure of "connectivity." It is positive when the two variables you have at hand are positively connected. Covariance is a linear measure of "connectivity....
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Waiting for answer What is the formula of the expected value of a geometric ran...
If you have a geometric distribution with parameter ##=p##, then the expected value or mean of the distribution is ... expected value ##=1/p## For example, if ##p=1/3##, then the ex...
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Waiting for answer What is the sample standard deviation formula?
s= ## [(xmean)/(n1)]^(1/2)## there is one difference between sample and population std deviation is degree of freedom. In sample , n observations are free to change whereas 1 is not that is use for estimating a population parameter.
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Waiting for answer What is the definition of a "success" in a binomial setting?
In a Binomial setting, there are only two possible outcomes per try. Depending on what you want, you call one of the possibilities Fail and the other one Succes. Example : You may call rolling a 6 with a die Succes, and a non6 a Fail. Depending on the conditions of the game, rolling a 6 may cost...
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Waiting for answer What is the purpose of a measure of center in Statistics?
Measures of center are a way to try capture the nonrandomness of a population or a random variable.This may sound a bit confusing,so I will walk through the 3 most common measures of center and explain how they try to do that. Mean . The mean is the most common measure of center and it tries to...
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Waiting for answer A test consists of 910 true or false questions. If the stude...
##sqrt{910 * 0.5 * 0.5}=sqrt{227.5} approx 15.08##. The number ##X## of correct guesses in ##n=910## trials is a binomial random variable with probability ##p=0.5## of success. The...
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Waiting for answer The probability that a contractor will get a plumbing contra...
##19/45##, The procedure is explained below. A is the event of getting a plumbing contract and p(A) = ##2/3##. B is the event of getting electrical contract and p(B) = ##5/9##. A##...
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Waiting for answer For a normal distribution, mean u=8. Find standard deviatio...
The standard deviation is ##sigma=1.5## The zscore is ##=(rmu)/sigma## Here we know. ##mu=8## and ##P (6 r 10)=0.5 ## Therefore, ##P(8 r 10)=0.25## We look for the probabi...
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Waiting for answer What is the difference between the line of best fit and the...
Nothing ... they are the same thing. Least squares line minimizes the distance between the line and the raw data points which would be the same objective for a line of best fit. ho...
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