Andrew buys 8 pounds of apples for $11.60. He wants to know and use the unit rate of the cost per pound.

Interpreting composite functions in the real world The volume of air in a balloon is represented by the function v(r)=4/3 ³, whe

adoni [48]

There are two true statements:

When the function is composed with r, the composite function is V(t) = (1/48) · π · t⁶.
V(r(6)) shows that the volume is 972π cubic inches after 6 seconds.

<h3>How to use composition between two function</h3>

Let be f and g two functions, there is a composition of f with respect to g when the domain of f is equal to the range of g. In this question, the domain variable of the function V(r) is replaced by substitution.

If we know that V(r) = (4/3) · π · r³ and r(t) = (1/4) · t², then the composite function is:

V(t) = (4/3) · π · [(1/4) · t²]³

V(t) = (4/3) · π · (1/64) · t⁶

V(t) = (1/48) · π · t⁶

There are two true statements:

When the function is composed with r, the composite function is V(t) = (1/48) · π · t⁶.
V(r(6)) shows that the volume is 972π cubic inches after 6 seconds.

To learn on composition between functions: brainly.com/question/12007574

#SPJ1

7 0

2 years ago

What is this please help?

mestny [16]

Answer:

y = 2/3x - 1

Step-by-step explanation:

The simpliest way to determine the slope of the line is to see the rise over run of the line. In this case, we are given two points which are at (0, -1) and (3,1)

By calculating rise of run, we can see that the starting point goes up by 2 units, from -1 to 1 and goes to the right 3 units, from 0 to 3

In this case, that means we have a slope of 2/3x.

The +b plays into the y-intercept of the line, which is actually the same of one of our points: (0,-1)

Since this number is a negative, it would actually be y = (2/3)x + (-1) which is the same as y=2/3x - 1

7 0

3 years ago

23. A certain type of gasoline is supposed to have a mean octane rating of at least 90. Suppose measurements are taken on of 5 r

Nostrana [21]

Answer:

a) $p_v =P(Z$

b) Since $p_v$ we can reject the null hypothesis at the significance level given. So based on this we can commit type of Error I.

Because Type I error " is the rejection of a true null hypothesis".

c) $P(\bar X >90)=1-P(Z$

$1-P(Z$

d) For this case we need a z score that accumulates 0.02 of the area on the right tail and 0.98 on the left tail and this value is z=2.054

And we can use this formula:

$2.054=\frac{90-89}{\frac{0.8}{\sqrt{n}}}$

And if we solve for n we got:

$n = (\frac{2.054 *0.8}{1})^2=2.7 \approx 3$

Step-by-step explanation:

Previous concepts and data given

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

We can calculate the sample mean and deviation with the following formulas:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

$s=\sqrt{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}$

$\bar X=88.96$ represent the sample mean

$s=1.011$ represent the sample standard deviation

n=5 represent the sample selected

$\alpha$ significance level

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is less than 90, the system of hypothesis would be:

Null hypothesis: $\mu \geq 90$

Alternative hypothesis: $\mu < 90$

If we analyze the size for the sample is < 30 and we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{88.96-90}{\frac{0.8}{\sqrt{5}}}=-2.907$

Part a

P-value

First we need to calculate the degrees of freedom given by:

$df=n-1=5-1 = 4$

Then since is a left tailed test the p value would be:

$p_v =P(Z$

Part b

Since $p_v$ we can reject the null hypothesis at the significance level given. So based on this we can commit type of Error I.

Because Type I error " is the rejection of a true null hypothesis".

Part c

We want this probability:

$P(\bar X$

The best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\frac{\sigma}{\sqrt{n}}}$

If we apply this formula to our probability we got this:

$P(\bar X >90)=1-P(Z$

$1-P(Z$

Part d

For this case we need a z score that accumulates 0.02 of the area on the right tail and 0.98 on the left tail and this value is z=2.054

And we can use this formula:

$2.054=\frac{90-89}{\frac{0.8}{\sqrt{n}}}$

And if we solve for n we got:

$n = (\frac{2.054 *0.8}{1})^2=2.7 \approx 3$

7 0

3 years ago

A bag contains nine red balls, four green balls, and fifteen yellow balls. What is the probability of pulling out one red ball?

Papessa [141]

Answer:

9/28

Step-by-step explanation:

9+4+15=28 total balls

9= total red balls

total red balls/total balls= probability of pulling out one red ball

9/28

(Can I have brainliest?)

8 0

3 years ago

PLZ PLZ HELP ME. THANKYOU. WILL GIVE BRAINLIEST

Alex Ar [27]

1. One solution
2.one solution
3.no solution
4.one solution
Hope this helped!

6 0

3 years ago