Question

conception clear up about sample variance

1. I heard that when the n is getting bigger, then the sample variance will be zero. I don't understand here,variance means the distance between the mean and the data value , in here does the mean is sample mean or population mean???

2. if the sample variance is 0, then all the data value will be same as the mean???

I am so confused, because how could that be possible, if we have large sample size n then, variance will be zero and all the data value will be same as the true mean?

Please be able to follow up the comment

Answer #1

The mean used is sample mean while calculating the variance.

when the n is getting bigger, then the sample variance will be zero this hold for very large n that is some Millions of sample.

So, the assumption about the sample is that most of the sample values are close to each other where as teh population values are very far.

So, when sample values are closer the numerator is small and with large value of n ( in Millions ) then denominator is very large hence the value of variance is almost zero It is never exact zero it is approaching to 0 ( iit might be 0.0000001 ) but not exactly zero.

Conception about hypothesis test:
Q1. my professor said if the null hypothesis is true, then it is
normal distribution but what does that mean? because sometimes we
will reject the H0, does that mean if we reject it then it is not
normal distribution?
Q2. sometimes we will have H0: u=30 something like that, but I
don't understand as i was told that we don't know the population
value; however u is the population value so i am confused. Plus,...

The following set of data is from a sample of
n equals 7n=7.
13 4 1 10 3 4
713 4 1 10 3 4 7
a. Compute the mean, median, and mode.
b. Compute the range, variance, standard deviation, and
coefficient of variation.
c. Compute the Z scores. Are there any outliers?
d. Describe the shape of the data set.
I am having a hard time getting the variance.

1. In one-sample t test, the difference between the mean
of your sample and μ increases. Will t-value and P-value will
increase, decrease, get closer to zero, or farther from
zero?
2. In a one sample t test, the variance of your sample
increases. Will t-value and P-value will increase, decrease, get
closer to zero, or farther from zero?
3. In a two sample t test, the difference between the
means of your samples decreases. Will t-value and P-value will...

Looking at my answers, I was am always off buy about range of .1
to .4 from the correct answer that is stated. I am having a really
tough time trying to figure out how to get my number to be exactly
like what is shown as correct so I need a little help with figuring
out what I am doing wrong. Here is an example of a question I just
cant seem to figure out. I'll show all my...

I am having trouble deciding what is true for these questions. I
thought I had the right answers but they keep getting marked wrong.
For Question 1, I chose option 2, as I though all the others to be
false. For Question 4 I chose option 4, as I learned that the
z-scores of the mean and standard deviation were always 0 and 1,
respectively. For question 5 I chose option 4 as well.
Which one of the following statements...

A researcher is studying treatments for agoraphobia with panic
disorder. The treatments are to be the drug Imipramine at the two
doses 1.5 mg per kg of body weight and 2.5 mg per kg of body
weight. There will also be a control group given a placebo. Thirty
patients were randomly divided into three groups of ten each. One
group was assigned to the control, and the other two groups were
assigned to the two drug treatments. After twenty-four weeks...

1.-To study the effect of temperature on yield in a chemical
process, five batches were produced at each of three temperature
levels. The results follow.
Temperature
50°C
60°C
70°C
33
30
22
24
30
28
36
35
29
39
23
31
28
27
35
Construct an analysis of variance table. (Round your values for
MSE and F to two decimal places, and your p-value
to four decimal places.)
Source
of Variation
Sum
of Squares
Degrees
of Freedom
Mean
Square
F...

T-tests are used when you want to examine differences but you do
not know everything about the population. There are three types of
t-tests that you may choose to do: one-sample t-test, independent
sample t-test, or dependent sample t-test. You can calculate these
by hand, in SPSS, or in Excel. The instructions below can be used
for SPSS and your textbook offers instructions for using Excel.
Single-sample t-tests
These tests are used when you want to determine the
probability that...

1.The sample mean is an unbiased estimator for
the population mean. This means:
The sample mean always equals the population mean.
The average sample mean, over all possible samples, equals the
population mean.
The sample mean will only vary a little from the population
mean.
The sample mean has a normal distribution.
2.Which of the following statements is
CORRECTabout the sampling distribution of the
sample mean:
The standard error of the sample mean will decrease as the
sample size increases....

i. A researcher estimated the proportion of voters who favor the
Democratic candidate in an election. Based on 500 people she
calculates the 95% confidence interval for the population
proportion p: 0.123 <p<0.181.
Which of the following is a valid interpretation of this
confidence interval ?______
a. There is a 95% chance that the true value of p lies between
0.123 and 0.181
b. If many different samples of 500 were selected
and a confidence interval was constructed based on...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 22 minutes ago

asked 36 minutes ago

asked 40 minutes ago

asked 47 minutes ago

asked 48 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago