50 points go for it! Why are dinosars good pets

A classic rock radio station claims to play an average of 50 minutes of music every hour. However, it seems that every time you

tia_tia [17]

Answer:

a) $47.917-1.796\frac{2.811}{\sqrt{12}}=46.460$

$47.917+1.796\frac{2.811}{\sqrt{12}}=49.374$

b) Null hypothesis: $\mu =50$

Alternative hypothesis: $\mu \neq 50$

And after analyze the interval obtained the upper limit not contains the value of 50, so then we can conclude that the claim is not satisfied for this case, and the population mean seems to be lower than 50 at 10% of significance.

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

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 have the following data: 44 49 45 51 49 53 49 44 47 50 46 48

And we can calculate the sample mean and deviation with the following formulas:

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

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

And replacing we got:

$\bar X= 47.917, s= 2.811$

$\mu$ population mean (variable of interest)

n=12 represent the sample size

Part a: Calculate the confidence interval

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

The degrees of freedom are given:

$df= n-1= 12-1=11$

Since the Confidence is 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.05,11)".And we see that $t_{\alpha/2}=1.796$

Now we have everything in order to replace into formula (1):

$47.917-1.796\frac{2.811}{\sqrt{12}}=46.460$

$47.917+1.796\frac{2.811}{\sqrt{12}}=49.374$

Part b

For this case the system of hypothesis are:

Null hypothesis: $\mu =50$

Alternative hypothesis: $\mu \neq 50$

And after analyze the interval obtained the upper limit not contains the value of 50, so then we can conclude that the claim is not satisfied for this case, and the population mean seems to be lower than 50 at 10% of significance.

6 0

3 years ago

I keep getting exactly 50%! Help!

Y_Kistochka [10]

Total = 242 + 307 = 549 but 242 ordered salad
so
242 / 549 = 0.4408 = 44.08%

answer
C. 44.08%

6 0

3 years ago

Read 2 more answers

Assume f(x)=-2x+8 and g(x)=3x. what is the value of (g o f)(3)

Olin [163]

Answer:

6

Step-by-step explanation:

(g o f)(3) = g(f(3))

We can find f(3) using its formula with x=3:

f(3) = -2·3 +8 = -6 +8 = 2

Now, we can find g(2) using its formula with x=2:

g(2) = 3·2 = 6

So, the composition value is ...

(g o f)(3) = 6

7 0

3 years ago

how much would $100 invested at 8% interest compounded annually be worth after 15 years? Round your answer to the nearest cent.

svet-max [94.6K]

To calculate problems abound about compounding interest use the equation A = P (1 + r/n)^(nt), where A is the future price, P is the principal amount, r is the interest rate, n is the number of times the interest is compounded per year and t for the total years. To solve, A = 100 (1 + 0.08/1)^(1 x 15) = 317.22.

5 0

3 years ago

Read 2 more answers

“Write an equation and solve for the unknown” I know it’s a lot but can someone help me with this

Svetradugi [14.3K]

Answer:

g) x = 30

h) x = 30

i) m = 55

j) x = 24

k) k = 45

Step-by-step explanation:

G)

all angles of a triangle add up to 180.

the square in the bottom right of the triangle is 90 btw

2x + x + 90 = 180

3x + 90 = 180

3x + 90 - 90 = 180 - 90

3x = 180 - 90

3x = 90

3x/3 = 90/3

x = 30

H)

this is an Isosceles triangle.

that means the bottom two angles are equal.

75 + 75 + x = 180

x + 150 = 180

x + 150 - 150 = 180 - 150

x = 180 - 150

x = 30

I)

2m is supplementary to the bottom right angle of the triangle.

that means they add together to make 180.

80 + 30 + (180 - 2m) = 180

110 - 2m = 180 - 180

110 - 2m = 0

110 = 2m

110/2 = m

55 = m

J)

to save time I'm not going to write out the steps, its the same as the i.

2x + 3x + (180 - 120 ) = 180

5x + 60 = 180

5x = 180 - 60

5x = 120

x = 120/5

x = 24

K)

imagine this as a triangle and a square.

sorry I'm not sure how to explain this -.-

but the equation would be

k + k + 90 = 180

2k + 90 = 180

2k = 180 - 90

2k = 90

k = 45

L)

Im not sure how to solve this, I'm sorry :( hope you figure it out!

5 0

3 years ago