In circle C, r = 32 units.

Alekssandra [29.7K]

The correct answer is B.

7 0

3 years ago

An investigator thinks that people under the age of forty have vocabularies that are different than those of people over sixty y

Kay [80]

Answer:

$t=\frac{(14-20)-0}{\sqrt{\frac{5^2}{31}+\frac{6^2}{31}}}}=-4.28$

Now we can calculate the p value with the following probability:

$p_v =2*P(t_{60}$

The p value is a very low value so then we have enough evidence to reject the null hypothesis and we can conclude that people under the age of forty have vocabularies that are different than those of people over sixty years of age.

Step-by-step explanation:

Information given

$\bar X_{1}=14$ represent the mean for sample 1 (younger)

$\bar X_{2}=20$ represent the mean for sample 2 (older)

$s_{1}=5$ represent the sample standard deviation for 1

$s_{f}=6$ represent the sample standard deviation for 2

$n_{1}=31$ sample size for the group 2

$n_{2}=31$ sample size for the group 2

t would represent the statistic

System of hypothesis

We want to test if that people under the age of forty have vocabularies that are different than those of people over sixty years of age, the system of hypothesis are:

Null hypothesis: $\mu_{1}-\mu_{2}=0$

Alternative hypothesis: $\mu_{1} - \mu_{2}\neq 0$

The statistic is given by:

$t=\frac{(\bar X_{1}-\bar X_{2})-\Delta}{\sqrt{\frac{\sigma^2_{1}}{n_{1}}+\frac{\sigma^2_{2}}{n_{2}}}}$ (1)

And the degrees of freedom are given by $df=n_1 +n_2 -2=31+31-2=60$

Replacing the info given we got:

$t=\frac{(14-20)-0}{\sqrt{\frac{5^2}{31}+\frac{6^2}{31}}}}=-4.28$

Now we can calculate the p value with the following probability:

$p_v =2*P(t_{60}$

The p value is a very low value so then we have enough evidence to reject the null hypothesis and we can conclude that people under the age of forty have vocabularies that are different than those of people over sixty years of age.

6 0

2 years ago

What is the common ratio between successive terms in the sequence?

ruslelena [56]

Answer:

1/3

Step-by-step explanation:

the formula of common ratio is given as

$r = \frac{a2}{a1}$

a1= 27 ,a2=9

r= 9/27

r= 1/3

3 0

2 years ago

A company claims that 80% of its customers are under 30. You suspect it is less than this. You take a random sample of 200 custo

son4ous [18]

Step-by-step explanation:

What we are trying to show is the alternative hypothesis. Here, we are trying to show that what the company claims is wrong; less than 80% of the company's customers are under 30.

8 0

2 years ago

Devon rented a U Haul truck for $48 for 4 hours plus $13.50 per each hour you go over. At the end of the day, his total bill was

Rasek [7]

Answer:

You need to write an equation to find the answer to this:

h = hours

48 + 13.5h = 112.50 -First you need to subtract 48 from both sides

48 - 48 + 13.5h = 112.50 - 48

13.5h = 64.5 -Now divide both sides by 13.5

13.5h / 13.5 = 64.5 / 13.5

h = 4.77777778

However, I would just round to 5.

I hope this helps!

-Mikayla

3 0

3 years ago