Your friend's house is 4.5 miles north and 6 miles east of the firehouse. How far is your friend's house from the firehouse?

A sociologist wishes to see if it is true that for a certain group of professional women, the average age at which they have the

Vadim26 [7]

Answer:

$Z = 2.1\ is\ higher\ than\ 1.96, we\ reject\ H_o$

Step-by-step explanation:

The explanation of given question is described below:

Here, the test of hypothesis states that

$H_o : Mean = 28.6$

$H_a : Mean\ which\ is\ not\ equals\ 28.6$

The test statistic is

$Z = \frac{(\bar X - Mean)}{\frac{Population\ standard\ deviation}{vn} }$

$Z = \frac{(30.06 - 28.6)}{\frac{4.18}{6} }$

= 2.1

According to the given data α = 0.05,

So, the major value is

$IZ(0.025)I = 1.96$

(refer to the standard normal table) .

Finally

$Z = 2.1\ is\ higher\ than\ 1.96, we\ reject\ H_o$

3 0

2 years ago

A certain type of thread is manufactured with a mean tensile strength of 78.3 kilograms and a standard deviation of 5.6 kilogram

azamat

Answer:

(a) The variance decreases.

(b) The variance increases.

Step-by-step explanation:

According to the Central Limit Theorem if we have a population with mean μ and standard deviation σ and we take appropriately huge random samples (n ≥ 30) from the population with replacement, then the distribution of the sample mean will be approximately normally distributed.

Then, the mean of the sample mean is given by,

$\mu_{\bar x}=\mu$

And the standard deviation of the sample mean is given by,

$\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}$

The standard deviation of sample mean is inversely proportional to the sample size, n.

So, if n increases then the standard deviation will decrease and vice-versa.

(a)

The sample size is increased from 64 to 196.

As mentioned above, if the sample size is increased then the standard deviation will decrease.

So, on increasing the value of n from 64 to 196, the standard deviation of the sample mean will decrease.

The standard deviation of the sample mean for n = 64 is:

$\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}=\frac{5.6}{\sqrt{64}}=0.7$

The standard deviation of the sample mean for n = 196 is:

$\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}=\frac{5.6}{\sqrt{196}}=0.4$

The standard deviation of the sample mean decreased from 0.7 to 0.4 when n is increased from 64 to 196.

Hence, the variance also decreases.

(b)

If the sample size is decreased then the standard deviation will increase.

So, on decreasing the value of n from 784 to 49, the standard deviation of the sample mean will increase.

The standard deviation of the sample mean for n = 784 is:

$\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}=\frac{5.6}{\sqrt{784}}=0.2$

The standard deviation of the sample mean for n = 49 is:

$\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}=\frac{5.6}{\sqrt{49}}=0.8$

The standard deviation of the sample mean increased from 0.2 to 0.8 when n is decreased from 784 to 49.

Hence, the variance also increases.

6 0

2 years ago

give an example on an addition problem in which you would and would not group the addends differently to add

Murrr4er [49]

Addends are any of the numbers added together in an equation.

The only time their grouping would matter would be if there were parentheses used to alter the normal Order of Operations.

For ex:
2 - (8 + 3) here, the 8 and 3 have to be grouped together before doing the subtraction.

Any addition problem without parentheses can be used for one where the grouping doesn't matter

3 0

2 years ago

Kenise is looking for a job that has benefits. She'd like to work in one place and not have to search for a new job anytime soon

solong [7]

Answer:

Kenise is looking for a job that has benefits. She'd like to work in one place and not have to search for a new job anytime soon. Kenise is looking for a Full-time job. She would most likely be paid an hourly wage, by the project.

5 0

2 years ago

Read 2 more answers

Sterre charges $35 to file tax returns, but files for free if she only needs the easiest form. Then she donates $2 to clean wate

borishaifa [10]

We have been given that Sterre charges $35 to file tax returns, but files for free if she only needs the easiest form. Also, she donates $2 to clean water projects per tax return she files.

Further we know that Sterre charged $7,245 and made a donation of $1,242 this year for the tax returns she filed.

Let x be the number of free income tax returns and y be the number of $35 income tax returns.

Therefore, we can set up:

$0\times x+35\times y=7245\Rightarrow 35y=7245\Rightarrow y=\frac{7245}{35}=207$

Since she donates $2 for each return that she files, therefore, we can set up:

$2(x+y)=1242\Rightarrow x+y=621\Rightarrow x+207=621\Rightarrow x=414$

Therefore,

Sterre filed 414 tax returns for free and filed 207 tax returns for $35.

7 0

2 years ago