Exam 7: Continuous Probability Distributions

IT Graduates Salary: The recent average starting salary for new college graduates in IT systems is $47,500. Assume salaries are normally distributed with a standard deviation of $4,500. -What percent of starting salaries are no more than $42,250?

(Short Answer)

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Question 61

As the degrees of freedom approach infinity, the values of a Student t distribution approach those of a standard normal distribution.

(True/False)

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Question 62

Given that Z is a standard normal variable, the variance of Z:

(Multiple Choice)

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Question 63

The value of an F distribution with v₁ = 6 and v₂ = 9 degrees of freedom such that the area to its right is 0.05 is 3.37.

(True/False)

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Question 64

Electronics Test: The time it takes a student to finish a electronics test has a uniform distribution between 50 and 70 minutes. -Find the probability that a student will take no less than 55 minutes to finish the test.

(Short Answer)

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Question 65

In practice, we frequently use a continuous distribution to approximate a discrete one when the number of values the variable can assume is countable but very large.

(True/False)

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Question 66

Waiting Time: The length of time patients must wait to see a doctor at an emergency room in a large hospital has a uniform distribution between 40 minutes and 3 hours. -What is the probability that a patient would have to wait no more than one hour?

(Short Answer)

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Question 67

The probability that Z is less than-2 is the same as one minus the probability that Z is greater than +2.

(True/False)

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Question 68

Lamont took a psychology exam whose mean was 70 with standard deviation 5. He also took a calculus exam whose mean was 80 with standard deviation 10. He scored 85 on both exams. On which exam did he do better compared to the other students who took the exam?

(Multiple Choice)

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Question 69

Suppose X has a normal distribution with mean 70 and standard deviation 5. The 50^th percentile of X is 70.

(True/False)

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Question 70

A(n) ____________________ random variable is one that assumes an uncountable number of possible values.

(Short Answer)

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Question 71

The 10^th percentile of a Z distribution has 10% of the Z-values lying above it.

(True/False)

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Question 72

Most values of a standard normal distribution lie between:

(Multiple Choice)

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Question 73

The expected value of the Student t distribution is zero.

(True/False)

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Question 74

We standardize a random variable by subtracting its and dividing by its .

(Short Answer)

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Question 75

A probability density function shows the probability for each value of X.

(True/False)

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Question 76

IT Graduates Salary: The recent average starting salary for new college graduates in IT systems is $47,500. Assume salaries are normally distributed with a standard deviation of $4,500. -What is the cutoff for the bottom 5% of the salaries?

(Short Answer)

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Question 77

Suppose X has a chi-squared distribution with 10 degrees of freedom. The variance of X is:

(Multiple Choice)

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Question 78

Calculus Scores: Scores of high school students on a national calculus exam were normally distributed with a mean of 86 and a standard deviation of 4. (Total possible points = 100.) -What is the probability that a randomly selected student will have a score of 80 or higher?

(Short Answer)

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Question 79

The mean of the standard normal distribution is and the standard deviation is .

(Short Answer)

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Question 80

Showing 61 - 80 of 149

IT Graduates Salary: The recent average starting salary for new college graduates in IT systems is $47,500. Assume salaries are normally distributed with a standard deviation of $4,500. -What percent of starting salaries are no more than $42,250?

As the degrees of freedom approach infinity, the values of a Student t distribution approach those of a standard normal distribution.

Given that Z is a standard normal variable, the variance of Z:

The value of an F distribution with v₁ = 6 and v₂ = 9 degrees of freedom such that the area to its right is 0.05 is 3.37.

Electronics Test: The time it takes a student to finish a electronics test has a uniform distribution between 50 and 70 minutes. -Find the probability that a student will take no less than 55 minutes to finish the test.

In practice, we frequently use a continuous distribution to approximate a discrete one when the number of values the variable can assume is countable but very large.

Waiting Time: The length of time patients must wait to see a doctor at an emergency room in a large hospital has a uniform distribution between 40 minutes and 3 hours. -What is the probability that a patient would have to wait no more than one hour?

The probability that Z is less than-2 is the same as one minus the probability that Z is greater than +2.

Lamont took a psychology exam whose mean was 70 with standard deviation 5. He also took a calculus exam whose mean was 80 with standard deviation 10. He scored 85 on both exams. On which exam did he do better compared to the other students who took the exam?

Suppose X has a normal distribution with mean 70 and standard deviation 5. The 50^th percentile of X is 70.

A(n) ____________________ random variable is one that assumes an uncountable number of possible values.

The 10^th percentile of a Z distribution has 10% of the Z-values lying above it.

Most values of a standard normal distribution lie between:

The expected value of the Student t distribution is zero.

We standardize a random variable by subtracting its and dividing by its .

A probability density function shows the probability for each value of X.

IT Graduates Salary: The recent average starting salary for new college graduates in IT systems is $47,500. Assume salaries are normally distributed with a standard deviation of $4,500. -What is the cutoff for the bottom 5% of the salaries?

Suppose X has a chi-squared distribution with 10 degrees of freedom. The variance of X is:

Calculus Scores: Scores of high school students on a national calculus exam were normally distributed with a mean of 86 and a standard deviation of 4. (Total possible points = 100.) -What is the probability that a randomly selected student will have a score of 80 or higher?

The mean of the standard normal distribution is and the standard deviation is .

What Is Statistics

Graphical and Tabular Descriptive Techniques

Numerical Descriptive Techniques

Data Collection and Sampling

Probability

Random Variables and Discrete Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About a Population

Inference About Comparing Two Populations, Part 1

Inference About Comparing Two Populations, Part 2

Analysis of Variance

Chi-Squared Tests

Simple Linear Regression and Correlation

Multiple Regression

Review of Statistical Inference

Filters

Exam 7: Continuous Probability Distributions

IT Graduates Salary: The recent average starting salary for new college graduates in IT systems is $47,500. Assume salaries are normally distributed with a standard deviation of $4,500. -What percent of starting salaries are no more than $42,250?

As the degrees of freedom approach infinity, the values of a Student t distribution approach those of a standard normal distribution.

Given that Z is a standard normal variable, the variance of Z:

The value of an F distribution with v1 = 6 and v2 = 9 degrees of freedom such that the area to its right is 0.05 is 3.37.

Electronics Test: The time it takes a student to finish a electronics test has a uniform distribution between 50 and 70 minutes. -Find the probability that a student will take no less than 55 minutes to finish the test.

In practice, we frequently use a continuous distribution to approximate a discrete one when the number of values the variable can assume is countable but very large.

Waiting Time: The length of time patients must wait to see a doctor at an emergency room in a large hospital has a uniform distribution between 40 minutes and 3 hours. -What is the probability that a patient would have to wait no more than one hour?

The probability that Z is less than-2 is the same as one minus the probability that Z is greater than +2.

Lamont took a psychology exam whose mean was 70 with standard deviation 5. He also took a calculus exam whose mean was 80 with standard deviation 10. He scored 85 on both exams. On which exam did he do better compared to the other students who took the exam?

Suppose X has a normal distribution with mean 70 and standard deviation 5. The 50th percentile of X is 70.

A(n) ____________________ random variable is one that assumes an uncountable number of possible values.

The 10th percentile of a Z distribution has 10% of the Z-values lying above it.

Most values of a standard normal distribution lie between:

The expected value of the Student t distribution is zero.

We standardize a random variable by subtracting its ____________________ and dividing by its ____________________.

A probability density function shows the probability for each value of X.

IT Graduates Salary: The recent average starting salary for new college graduates in IT systems is $47,500. Assume salaries are normally distributed with a standard deviation of $4,500. -What is the cutoff for the bottom 5% of the salaries?

Suppose X has a chi-squared distribution with 10 degrees of freedom. The variance of X is:

Calculus Scores: Scores of high school students on a national calculus exam were normally distributed with a mean of 86 and a standard deviation of 4. (Total possible points = 100.) -What is the probability that a randomly selected student will have a score of 80 or higher?

The mean of the standard normal distribution is ____________________ and the standard deviation is ____________________.

What Is Statistics

Graphical and Tabular Descriptive Techniques

Numerical Descriptive Techniques

Data Collection and Sampling

Probability

Random Variables and Discrete Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About a Population

Inference About Comparing Two Populations, Part 1

Inference About Comparing Two Populations, Part 2

Analysis of Variance

Chi-Squared Tests

Simple Linear Regression and Correlation

Multiple Regression

Review of Statistical Inference

Filters

The value of an F distribution with v₁ = 6 and v₂ = 9 degrees of freedom such that the area to its right is 0.05 is 3.37.

Suppose X has a normal distribution with mean 70 and standard deviation 5. The 50^th percentile of X is 70.

The 10^th percentile of a Z distribution has 10% of the Z-values lying above it.

We standardize a random variable by subtracting its and dividing by its .

The mean of the standard normal distribution is and the standard deviation is .