If you go out 3 standard deviation units on both sides of the mean in a normal distribution, what percentage of the cases will be captured?

Q: In a standard normal distribution, the mean is always 0 Does this suggest that half of the scores…

A: In a standard normal distribution, the mean is always 0 and the Standard deviation is always equal…

Q: The mean of a normal probability distribution is 120 the standard deviation is 10. About what…

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Q: what percent of the data falls within 2 standard deviations of the mean?

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Q: If you know that you have data that follows a normal distribution with a mean of 75 and standard…

A: Given that the data follows a normal distribution with a mean of 75 and standard deviation of 17.

Q: The mean of a normal probability distribution is 120 the standard deviation is 10. About what…

A:

Q: If the mean is zero and the standard deviation is one in a normal distribution, what type of normal…

A: We know that if the normal distribution has 2 parameters as mean, μ and standard deviation, σ, where…

Q: In a study about the life expectancy of 200 thirty-year old males, the mean is 65 and the standard…

A: Sample size(n)=200 Mean(μ)=65 Standard deviation(σ)=10  The proportion of the males who live past 75…

Q: What is the mean of the distribution? What is the standard deviation of the distribution?

A: Given Mean1=30 Mean2=27 n1=41 n2=57

Q: Let us suppose that the amount of bread consumed by adult Americans per day can be modeled by a…

A: Given: Mean(μ)  = 32 oz Standard deviation (σ) = 13.3 oz

Q: If the variance of a distribution is 16, the standard deviation is?

A: Solution: From the given information, the variance of a distribution is 16.

Q: Suppose you have a test with a mean of 66 and a standard deviation of 5. If you first increase…

A: Given Mean =66 Standard deviation=5

Q: if a distribution is normal with a population mean = 60 and population standard deviation = 15, what…

A: Let "X" be the scores that is normally distributed.

Q: Approximately what percentage of normally distributed data will fall within 2 standard deviations…

A: Based on the Concept of Empirical Rule: About 68% of the area under the curve falls within 1…

Q: What proportion of the students scored lower than 80 if the distribution of these grades can be…

A:

Q: In a normal distribution, mean is 60 and standard deviation is 5. How many of the cases have scores…

A: The probability between two specific numbers a and b in a normal distribution with mean μ and…

Q: The heights of NBA basketball players are normally distributed. Which is closest to the percentage…

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Q: It is possible to have a standard deviation of -1 for some data set? True or False

A: See the below solution

Q: Using the simplified version of the normal distribution, what percentage of the cases falls within 2…

A: It is given, A normal distribution with 2 standard deviation.

Q: How does one calculate the standard deviation?

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Q: 16. In a standardized test with a normal distribution of scores, the mean is 63 and the standard…

A: here use normal curve property and value near to center in curve have more chance to occur

Q: What are the characteristics of a normal distribution? What two characteristics make a distribution…

A: Given that  What are the characteristics of a normal distribution?   What two characteristics make a…

Q: What proportion of a normal distribution is located between the mean and z = -0.47?

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Q: In a Scrabble tournament, the scores were normally distributed and the mean score was 420.2 points…

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Q: What percent of cases ARE NOT between the mean and 0.21 standard deviations above the mean?

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Q: In a Scrabble tournament, the scores were normally distributed and the mean score was 420.2 points…

A:

Q: It is often quoted that in a normal distribution, 95% of the data lies 1.96 deviations either side…

A: Let X be the random variable   X~ Normal (0, 1)

Q: In a normal distribution, approximately what percent of data items fall within 1 standard deviation…

A: Empirical rules:1) P(μ-σ<X<μ+σ)=68%2) P(μ-2σ<X<μ+2σ)=95%3)P(μ-3σ<X<μ+3σ)=99.7%

Q: On a test that has a normal distribution, a score of 60 falls one standard deviation above the mean,…

A: Given that the test score has Normally distributed.  A score of 60 falls one standard deviation…

Q: If mean is 20 and standard deviation is 5, what value of x contain the lowest 20% of the…

A: Solution

Q: In a normal PD, the mean equals 1100 and the standard deviation equals 80. If you choose a sample of…

A: Solution: Let X be the random variable. From the given information, X follows normal distribution…

Q: A normal distribution has a mean of µ = 80 with σ = 20. What score separates the highest 40% of the…

A: The given distribution is normal with mean 80 and standard deviation 20.

Q: Suppose that the score on a reading test are normally distributed within a mean of 70 and a standard…

A:

Q: If a number is added to a data set which is far away from the arithmetic mean the what happens to…

A: There are two properties regarding the addition of a number to a data set and its effect on standard…

Q: What us the variance of a distribution having a standard deviation of 5.26?

A: Given, standard deviation=5.26 find variance=?

Q: A test was designed to have a mean of 80 and a standard deviation of 10. A random sample of 20…

A: Computation of test statistic value: The population standard deviation is given, σ = 10. Thus, in…

Q: What is the z score for 120 when mean is 100 and standard deviation is 5.

A: We have to find z score for 120 when mean is 100 and standard deviation is 5.

Q: In a normal distribution with a mean of 72 and a standard deviation of 12, what percentage of cases…

A: GivenMean(μ)=72standard deviation(σ)=12

Q: The variance of a sample of 81 observations equals 64. what is  standard deviation of the sample ?

A: Given data ,no of samples n=81Variance σ2=64Std. deviation σ= ?

Q: What are the characteristics of a normal distribution?

A: Normal distribution- It is a frequency distribution curve. It is also called bell shaped curve. In…

Q: What is the variance of a data set with mean score of 87.5 and a standard deviation of 2?

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Q: According to the Empirical Rule, in a Normal Distribution of data you will have

A: We know that Empirical rule : 68% data lies within one standard deviation of the Mean. ( μ ± σ) 95%…

Q: If a distribution is normal with μ = 60 and σ = 15, what proportion of the scores fall between 60…

A: If X~N(μ,σ2), then Z=X-μσ is called the standard normal variate. The mean and variance of a standard…

Q: The population average of a college test score of students is 100 with a standard deviation of 25.…

A:

Q: imagine the average score on an exam is 71 with a standard deviation of 10. If scores are normally…

A: If a random variable x has a distribution with mean µ and standard deviation σ, then the z-score is…

Q: IF THE VARIANCE OF A POPULATION IS 0.75, THE STANDARD DEVIATION MUST BE?

A: It is an important part of statistics . It is widely used .

Q: Suppose that the mean IQ score for University Students is 105, with a standard deviation of 7.…

A: Normal distribution is a continuous distribution which has many real life applications. Normal curve…

Equations and Inequations

Equations and inequalities describe the relationship between two mathematical expressions.

Linear Functions

A linear function can just be a constant, or it can be the constant multiplied with the variable like x or y. If the variables are of the form, x2, x1/2 or y2 it is not linear. The exponent over the variables should always be 1.