Find x <br> m Please and thank you

Kobe collected $18.50 more than amari, and DJ collected $12.25 less than Kobe. Altoghter the three boys collected $95.70. How mu

NNADVOKAT [17]

Dk collected 29.90 $

6 0

3 years ago

Read 2 more answers

In a survey of sleeping habits, 8400 national adults were selected randomly and contacted by telephone. Respondents were asked,

7nadin3 [17]

Answer:

C) 1.8 is a statistic and represents an estimate of the unknown value of a parameter of interest.

Step-by-step explanation:

<u>The complete question is</u>: In a survey of sleeping habits, 8400 national adults were selected randomly and contacted by telephone.

Respondents were asked: “Typically, how many times per week do you sleep less than 6 hours during the night?” On average, those surveyed reported an average of 1.8 nights per week in which they got less than 6 hours of sleep. Which of the following is true with respect to this scenario?

A) 8400 is the size of the population being studied.

B) 1.8 is a parameter and represents an estimate of the unknown value of a statistic of interest.

C) 1.8 is a statistic and represents an estimate of the unknown value of a parameter of interest.

D) None of the above

We are given that in a survey of sleeping habits, 8400 national adults were selected randomly and contacted by telephone.

On average, those surveyed reported an average of 1.8 nights per week in which they got less than 6 hours of sleep.

In the question 8400 is the sample size (n) as it is taken from the population to conduct a survey.

So, the statement is not true that 8400 is the size of the population being studied. It is the size of the sample being tested.

Also, the sample mean = 1.8 nights per week, it is sample or statistic value because it is calculated using sample size value and it is an estimate or representation of the population unknown parameter.

So, the correct statement is that 1.8 is a statistic and represents an estimate of the unknown value of a parameter of interest.

7 0

3 years ago

Find the poin on the graph 0f f(x)=1-x^2 that are closest to0(0,0)

zalisa [80]

Represent any point on the curve by (x, 1-x^2). The distance between (0, 0) and (x, 1-x^2) is

$\sqrt{(x-0)^2+(1-x^2-0)^2}=\sqrt{x^2+(1-x^2)^2}=\sqrt{x^2+1-2x^2+x^4}$

To make this easier, let's minimize the SQUARE of this quantity because when the square root is minimal, its square will be minimal.

So minimize $L=x^4-x^2+1$

Find the derivative of L and set it equal to zero.

$\frac{d}{dx}(L)=4x^3-2x \\ 4x^3-2x=0 \\ 2x(2x^2-1)=0$

This gives you $x=0$ or $x^2=\frac{1}{2} \\ x=\pm\sqrt{2}/2$

You can use the Second Derivative Test to figure out which value(s) produce the MINIMUM distance.

$\frac{d^2}{dx}=12x^2-2$

When x = 0, the second derivative is negative, indicating a relative maximum. When $x=\pm\frac{\sqrt{2}}{2}$ , the second derivative is positive, indicating a relative MINIMUM.

The two points on the curve closest to the origin are $\left( \pm\frac{\sqrt{2}}{2},\frac{1}{2} \right)$