Ask question

Ask question

All categories

2 years ago

13

wingspans of adult herons have approximate normal distribution with mean 125cm and a standard deviation 12cm. what proportion of

herons have wingspan of excatly 140cm?

1 answer:

Ymorist [56]2 years ago

7 0

Answer:

$P (X = 140) = 0$

Step-by-step explanation:

We know that the heron wingspan follow a normal distribution with an mean of 125 cm.

In this case we seek to find

$P (X = 140)$

If X is a random variable that represents the length of the heron wingspan, then X follows a normal distribution and therefore is a continuous random variable.

Then by definition of continuous random variable we have to:

$P (X = a) = 0$ where a is a constant.

That is to say that only the ranges of values can have a different probability of zero. The probability that a continuous random variable is equal to some exact value is always zero.

Finally we can conclude that

$P (X = 140) = 0$

You might be interested in

Please help I need help ASAP

Inessa [10]

Answer:

a 2.68

b 2.01

Step-by-step explanation:

1.34/2 =( 0.67 (F) )

(F)*4 = A

(F)*3 = B

6 0

1 year ago

What value of x is in the solution set of 2(3x – 1) ≥ 4x – 6?

Angelina_Jolie [31]

For this case we must find the value of the variable "x" of the following expression:

$2 (3x-1) \geq4x-6$

We apply distributive property to the terms within parentheses: $6x-2 \geq4x-6$

We subtract 4x on both sides:

$6x-4x-2 \geq-6\\2x-2 \geq-6$

We add 2 to both sides:

$2x \geq-6 + 2\\2x \geq-4$

We divide between 2 on both sides:

$x \geq \frac {-4} {2}\\x \geq-2$

Answer:

$x \geq-2$

5 0

1 year ago

Read 2 more answers

A theatre has the capacity to seat people across two levels, the Circle and

andriy [413]

Answer: $76.19\%$

Step-by-step explanation:

<h3> The complete exercise is: " A theatre has the capacity to seat people across two levels, the Circle, and the stalls. The ratio of the number of seats in the circle to a number of seats in the stalls is 2:5. Last Friday, the audience occupied all the 528 seats in the circle and $\frac{2}{3}$ of the seats in the stalls. What is the percentage of occupancy of the theatre last Friday?"</h3>

Let be "s" the total number of seats in the Stalls.

The problem says that the ratio of the number of seats in the Circle to the number of seats in the Stalls is $2:5$ .

Since the number of seats that were occupied last Friday was 528 seats, we can set up the following proportion:

$\frac{2}{5}=\frac{528}{s}$

Solving for "s", we get:

$s*\frac{2}{5}=528\\\\s=528*\frac{5}{2}\\\\s=1,320$

So the sum of the number of seats in the Circle and the number of seats in the Stalls, is:

$Total=1,320\ seats+528\ seats=1,848\ seats$

We know that $\frac{2}{3}$ of the seats in the Stalls were occupied. Then, the number of seat in the Stalls that were occupied is:

$(1,320)(\frac{2}{3})=880$

Therefore, the total number of seats that were occupied las Friday is:

$Total\ occupied=880\ seats+528\ seats=1,408\ seats$

Knowing this, we can set up the following proportion, where "p" is the the percentage of occupancy of the theatre last Friday:

$\frac{100}{1,848}=\frac{p}{1,408}$

Solving for "p", we get:

$(1,408)(\frac{100}{1,848})=p\\\\p=76.19\%$

8 0

1 year ago

What is the axis of symmetry of h(x) = –2x2 + 12x – 3?

Ksivusya [100]

h(x) = -2x2 + 12x - 3?

The axis of symmetry is :

x = 3

Hope this helps.

Welcome to Brainly!,

Davinia.

8 0

1 year ago

Read 2 more answers

a ball is thrown with a slingshot at a velocity of 110ft/sec at an angle of 20 degrees above the ground from a height of 4.5 ft.

satela [25.4K]

Answer:

$t=2.47\ s$

Step-by-step explanation:

The equation that models the height of the ball in feet as a function of time is

$h(t) = h_0 + s_0t -16t ^ 2$

Where $h_0$ is the initial height, $s_0$ is the initial velocity and t is the time in seconds.

We know that the initial height is:

$h_0 = 4.5\ ft$

The initial speed is:

$s_0 = 110sin(20\°)\\\\s_0 = 37.62\ ft/s$

So the equation is:

$h (t) = 4.5 + 37.62t -16t ^ 2$

The ball hits the ground when when $h(t) = 0$

So

$4.5 + 37.62t -16t ^ 2 = 0$

We use the quadratic formula to solve the equation for t

For a quadratic equation of the form

$at^2 +bt + c$

The quadratic formula is:

$t=\frac{-b\±\sqrt{b^2 -4ac}}{2a}$

In this case

$a= -16\\\\b=37.62\\\\c=4.5$

Therefore

$t=\frac{-37.62\±\sqrt{(37.62)^2 -4(-16)(4.5)}}{2(-16)}$

$t_1=-0.114\ s\\\\t_2=2.47\ s$

We take the positive solution.

Finally the ball takes 2.47 seconds to touch the ground

4 0

2 years ago