F(x)=3x^2-x+2; [-3,1]

From 19 measurements of a pressure controller, the mean operating pressure is 4.97 kPa with a standard deviation of 0.0461 kPa.

Semenov [28]

Answer:

$4.97-2.10\frac{0.0461}{\sqrt{19}}=4.95$

$4.97+2.10\frac{0.0461}{\sqrt{19}}=4.99$

So on this case the 95% confidence interval would be given by (4.95;4.99)

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".

$\bar X =4.97$ represent the sample mean

$\mu$ population mean (variable of interest)

s=0.0461 represent the sample standard deviation

n=19 represent the sample size

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)

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=19-1=18$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,18)".And we see that $t_{\alpha/2}=2.10$

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

$4.97-2.10\frac{0.0461}{\sqrt{19}}=4.95$

$4.97+2.10\frac{0.0461}{\sqrt{19}}=4.99$

So on this case the 95% confidence interval would be given by (4.95;4.99)

5 0

2 years ago

There are 210210210 students in a twelfth grade high school class. 909090 of these students have at least one sister and 1051051

BlackZzzverrR [31]

Answer:

(1) The value of P (A) is 0.4286.

(2) The value of P (B) is 0.50.

(3) The value of P (A ∩ B) is 0.2143.

(4) The the value of P (B|A) is 0.50.

(5) The events A and B are independent.

Step-by-step explanation:

The events are defined as follows:

A = a student in the class has a sister

B = a student has a brother

The information provided is:

N = 210

n (A) = 90

n (B) = 105

n (A ∩ B) = 45

The probability of an event E is the ratio of the favorable number of outcomes to the total number of outcomes.

$P(E)=\frac{n(E)}{N}$

The conditional probability of an event X provided that another event Y has already occurred is:

$P(X|Y)=\frac{P(A\cap Y)}{P(Y)}$

If the events X and Y are independent then,

$P(X|Y)=P(X)$

(1)

Compute the probability of event A as follows:

$P(A)=\frac{n(A)}{N}\\\\=\frac{90}{210}\\\\=0.4286$

The value of P (A) is 0.4286.

(2)

Compute the probability of event B as follows:

$P(B)=\frac{n(B)}{N}\\\\=\frac{105}{210}\\\\=0.50$

The value of P (B) is 0.50.

(3)

Compute the probability of event A and B as follows:

$P(A\cap B)=\frac{n(A\cap B)}{N}\\\\=\frac{45}{210}\\\\=0.2143$

The value of P (A ∩ B) is 0.2143.

(4)

Compute the probability of B given A as follows:

$P(B|A)=\frac{P(A\cap B)}{P(A)}\\\\=\frac{0.2143}{0.4286}\\\\=0.50$

The the value of P (B|A) is 0.50.

(5)

The value of P (B|A) = 0.50 = P (B).

Thus, the events A and B are independent.

6 0

3 years ago

Jed bought a generator that will run for 2 hours on a liter of gas. The gas tank on the generator is a rectangular prism with di

IceJOKER [234]

Answer:

The generator will run for 6 hours.

Step-by-step explanation:

First, find the volume of the gas tank that is on the generator. I am told that the gas tank is a rectangular prism that has the dimensions of 20 cm, 15 cm, and 10cm.

Area of any prism = height * width * length

Area of prism = 20 cm * 15 cm * 10 cm = 3,000 cm cubed

I am told the important info that 1,000 cm cubed = 1 liter

Therefore, 3,000 cm cubed = 3 liters

I am also told that the generator will run for 2 hours on 1 liter of gas

Lets make a ratio table:

Hours the generator will run for : liters of gas

2 : 1

6 : 3

the generator will run for 6 hours.

6 0

2 years ago

If x - 3 Is a factor P(x) = x ^ 3 - 7x ^ 2 + 15x - 9, which of the following represents the complete factorization for P(x) ?

sattari [20]

the answer is c, i just got this question

3 0

2 years ago

Select the possible values for x in the equation x2 = 108.

Rudiy27

Answer:

D. 6√3.

Step-by-step explanation:

x^2 = 108

x = +/- √108

x = +/- √36 * √3

x = +/- 6√3

7 0

2 years ago