Question 1

The sample mean is an unbiased estimate of the population mean.

Accepted Answer

A) True 
 B)False

Question 2

For sample size 16,the sampling distribution of the mean will be approximately normally distributed

Accepted Answer

A)  if the sample is normally distributed. 
B)  if the shape of the population is symmetrical. 
C)  if the sample standard deviation is known. 
D)  regardless of the shape of the population. 
A)  if the sample is normally distributed. 
B)  if the shape of the population is symmetrical. 
C)  if the sample standard deviation is known. 
D)  regardless of the shape of the population.

Question 3

Australian football salaries averaged $150,000 with a standard deviation of $80,000 in a recent year.Suppose a sample of 100 football players was taken.Find the approximate probability that the average salary of the 100 players exceeded $100,000.

Accepted Answer

A)  Approximately 1 
B)  0.2357 
C)  0.7357 
D)  Approximately 0 
A)  Approximately 1 
B)  0.2357 
C)  0.7357 
D)  Approximately 0

Question 4

The amount of bleach a machine pours into bottles has a mean of 1080 grams with a standard deviation of 4.5 grams.Suppose we take a random sample of 36 bottles filled by this machine.
-The probability that the mean of the sample is less than 1080.9 is _____.

Accepted Answer

The answer of The amount of bleach a machine pours...

Question 5

The owner of a fish market has an assistant who has determined that the weights of rainbow trout are normally distributed,with mean of 3.2 kilograms and standard deviation of 0.8 kilogram.
-What percentage of samples of 4 fish will have sample means between 3.0 and 4.0 kilograms?

Accepted Answer

A)  67% 
B)  29% 
C)  84% 
D)  16% 
A)  67% 
B)  29% 
C)  84% 
D)  16%

Question 6

A study at a university in New South Wales reveals that,historically,45% of their students are minority students.If random samples of size 75 are selected,the standard error of the proportions of students in the samples who are minority students is_________

Accepted Answer

The answer of A study at a university in New...

Question 7

The amount of bleach a machine pours into bottles has a mean of 1080 grams with a standard deviation of 4.5 grams.Suppose we take a random sample of 36 bottles filled by this machine.
-The probability that the mean of the sample exceeds 1080.3 grams is_____.

Accepted Answer

The answer of The amount of bleach a machine pours...

Question 8

Instruction 7.5
According to an article, 19% of the entire Australian population have high-speed access to the Internet. Random samples of size 200 are selected from the Australian population.
-Referring to Instruction 7.5,among all the random samples of size 200,_________ % will have more than 30% who have high-speed access to the Internet.

Accepted Answer

0.0000 or

Question 9

Instruction 7.2
The mean selling price of new homes in a country town over a year was $115,000. The population standard deviation was $25,000. A random sample of 100 new home sales from this town was taken.
-Referring to Instruction 7.2,what is the probability that the sample mean selling price was between $113,000 and $117,000?

Accepted Answer

0.5763 usi

Question 10

The owner of a fish market has an assistant who has determined that the weights of rainbow trout are normally distributed,with mean of 3.2 kilograms and standard deviation of 0.8 kilogram.
-If a sample of 25 fish yields a mean of 3.6 kilograms,what is the Z-score for this observation?

Accepted Answer

A)  1.875 
B)  18.750 
C)  2.500 
D)  0.750 
A)  1.875 
B)  18.750 
C)  2.500 
D)  0.750

Question 11

The sampling distribution of a sample statistic represents what would result if all possible samples from a population were drawn.

Accepted Answer

A) True 
 B)False

Question 12

A manufacturer of power tools claims that the average amount of time required to assemble their top-of-the-line table saw is 80 minutes with a standard deviation of 40 minutes
-Suppose a random sample of 64 purchasers of this table saw is taken.The mean of the sampling distribution of the sample mean is _____________minutes.

Accepted Answer

The answer of A manufacturer of power tools claims that...

Question 13

Suppose a sample of n = 50 items is drawn from a population of manufactured products and the weight,X,of each item is recorded.Prior experience has shown that the weight has a probability distribution with μ = 180 grams and σ = 75 grams.Which of the following is true about the sampling distribution of the sample mean if a sample size of 15 is selected?

Accepted Answer

A)  The shape of the sample distribution is approximately normal. 
B)  The standard deviation of the sampling distribution is 75 grams. 
C)  The mean of the sampling distribution is 180 grams. 
D)  All of the above are correct. 
A)  The shape of the sample distribution is approximately normal. 
B)  The standard deviation of the sampling distribution is 75 grams. 
C)  The mean of the sampling distribution is 180 grams. 
D)  All of the above are correct.

Question 14

Instruction 7.2
The mean selling price of new homes in a country town over a year was $115,000. The population standard deviation was $25,000. A random sample of 100 new home sales from this town was taken.
-Referring to Instruction 7.2,what is the probability that the sample mean selling price was between $114,000 and $116,000?

Accepted Answer

The answer of Instruction 7.2
The mean selling price of new...

Question 15

For sample size 1,the sampling distribution of the mean will be normally distributed

Accepted Answer

A)  only if the shape of the population is symmetrical. 
B)  regardless of the shape of the population. 
C)  only if the population values are positive. 
D)  only if the population is normally distributed. 
A)  only if the shape of the population is symmetrical. 
B)  regardless of the shape of the population. 
C)  only if the population values are positive. 
D)  only if the population is normally distributed.

Question 16

Sampling error can be reduced by taking larger sample sizes.

Accepted Answer

A) True 
 B)False

Question 17

The amount of pyridoxine (in grams)per multiple vitamin is normally distributed with $\mu$ = 110 grams and $\sigma$= 25 grams.A sample of 25 vitamins is to be selected.
-So,the middle 70% of all sample means will fall between what two values?

Accepted Answer

The answer of The amount of pyridoxine (in grams)per multiple...

Question 18

Instruction 7.3
The lifetimes of a certain brand of light bulbs are known to be normally distributed with a mean of 1,600 hours and a standard deviation of 400 hours. A random sample of 64 of these light bulbs is taken.
-Referring to Instruction 7.3,the probability is 0.20 that the sample mean lifetime differs from the population mean lifetime by at least how many hours?

Accepted Answer

64.08 hours using Ex

Question 19

A sampling distribution is a probability distribution for a statistic.

Accepted Answer

A) True 
 B)False

Question 20

Instruction 7.4
According to a survey, only 15% of customers who visited the web site of a major retail store made a purchase. Random samples of size 50 are selected.
-Referring to Instruction 7.4,the standard deviation of all the sample proportions of customers who will make a purchase after visiting the web site is _________

Accepted Answer

The answer of Instruction 7.4
According to a survey, only 15%...

The sample mean is an unbiased estimate of the population mean.

For sample size 16,the sampling distribution of the mean will be approximately normally distributed

Australian football salaries averaged $150,000 with a standard deviation of $80,000 in a recent year.Suppose a sample of 100 football players was taken.Find the approximate probability that the average salary of the 100 players exceeded $100,000.

The amount of bleach a machine pours into bottles has a mean of 1080 grams with a standard deviation of 4.5 grams.Suppose we take a random sample of 36 bottles filled by this machine. -The probability that the mean of the sample is less than 1080.9 is _____.

The owner of a fish market has an assistant who has determined that the weights of rainbow trout are normally distributed,with mean of 3.2 kilograms and standard deviation of 0.8 kilogram. -What percentage of samples of 4 fish will have sample means between 3.0 and 4.0 kilograms?

A study at a university in New South Wales reveals that,historically,45% of their students are minority students.If random samples of size 75 are selected,the standard error of the proportions of students in the samples who are minority students is_________

The amount of bleach a machine pours into bottles has a mean of 1080 grams with a standard deviation of 4.5 grams.Suppose we take a random sample of 36 bottles filled by this machine. -The probability that the mean of the sample exceeds 1080.3 grams is_____.

The owner of a fish market has an assistant who has determined that the weights of rainbow trout are normally distributed,with mean of 3.2 kilograms and standard deviation of 0.8 kilogram. -If a sample of 25 fish yields a mean of 3.6 kilograms,what is the Z-score for this observation?

The sampling distribution of a sample statistic represents what would result if all possible samples from a population were drawn.

For sample size 1,the sampling distribution of the mean will be normally distributed

Sampling error can be reduced by taking larger sample sizes.

The amount of pyridoxine (in grams)per multiple vitamin is normally distributed with $\mu$ = 110 grams and $\sigma$ = 25 grams.A sample of 25 vitamins is to be selected. -So,the middle 70% of all sample means will fall between what two values?

A sampling distribution is a probability distribution for a statistic.

Defining and Collecting Data

Organising and Visualising Data

Numerical Descriptive Measures

Basic Probability

Some Important Discrete Probability Distributions

The Normal Distribution and Other Continuous Distributions

Confidence Interval Estimation

Fundamentals of Hypothesis Testing: One-Sample Tests

Hypothesis Testing: Two-Sample Tests

Analysis of Variance

Simple Linear Regression

Introduction to Multiple Regression

Time-Series Forecasting and Index Numbers

Chi-Square Tests

Multiple Regression Model Building

Decision Making

Statistical Applications in Quality Management

Further Non-Parametric Tests

Filters

Exam 7: Sampling Distributions

The sample mean is an unbiased estimate of the population mean.

For sample size 16,the sampling distribution of the mean will be approximately normally distributed

Australian football salaries averaged $150,000 with a standard deviation of $80,000 in a recent year.Suppose a sample of 100 football players was taken.Find the approximate probability that the average salary of the 100 players exceeded $100,000.

The amount of bleach a machine pours into bottles has a mean of 1080 grams with a standard deviation of 4.5 grams.Suppose we take a random sample of 36 bottles filled by this machine. -The probability that the mean of the sample is less than 1080.9 is _____.

The owner of a fish market has an assistant who has determined that the weights of rainbow trout are normally distributed,with mean of 3.2 kilograms and standard deviation of 0.8 kilogram. -What percentage of samples of 4 fish will have sample means between 3.0 and 4.0 kilograms?

A study at a university in New South Wales reveals that,historically,45% of their students are minority students.If random samples of size 75 are selected,the standard error of the proportions of students in the samples who are minority students is_________

The amount of bleach a machine pours into bottles has a mean of 1080 grams with a standard deviation of 4.5 grams.Suppose we take a random sample of 36 bottles filled by this machine. -The probability that the mean of the sample exceeds 1080.3 grams is_____.

The owner of a fish market has an assistant who has determined that the weights of rainbow trout are normally distributed,with mean of 3.2 kilograms and standard deviation of 0.8 kilogram. -If a sample of 25 fish yields a mean of 3.6 kilograms,what is the Z-score for this observation?

The sampling distribution of a sample statistic represents what would result if all possible samples from a population were drawn.

For sample size 1,the sampling distribution of the mean will be normally distributed

Sampling error can be reduced by taking larger sample sizes.

The amount of pyridoxine (in grams)per multiple vitamin is normally distributed with μ\muμ = 110 grams and σ\sigmaσ = 25 grams.A sample of 25 vitamins is to be selected. -So,the middle 70% of all sample means will fall between what two values?

A sampling distribution is a probability distribution for a statistic.

Defining and Collecting Data

Organising and Visualising Data

Numerical Descriptive Measures

Basic Probability

Some Important Discrete Probability Distributions

The Normal Distribution and Other Continuous Distributions

Confidence Interval Estimation

Fundamentals of Hypothesis Testing: One-Sample Tests

Hypothesis Testing: Two-Sample Tests

Analysis of Variance

Simple Linear Regression

Introduction to Multiple Regression

Time-Series Forecasting and Index Numbers

Chi-Square Tests

Multiple Regression Model Building

Decision Making

Statistical Applications in Quality Management

Further Non-Parametric Tests

Filters

The amount of pyridoxine (in grams)per multiple vitamin is normally distributed with $\mu$ = 110 grams and $\sigma$ = 25 grams.A sample of 25 vitamins is to be selected. -So,the middle 70% of all sample means will fall between what two values?