(stupid answers will get reported)(alots of points)

Twenty-five randomly selected students were asked the number of movies they watched the previous week. The results are as follow

guajiro [1.7K]

Answer:

a) x = 1.52

b) s = 1.16

Step-by-step explanation:

We have that:

5 students watched 0 movies.

9 students watched 1 movie.

5 students watched 2 movies.

5 students watched 3 movies.

1 student watched 4 movies.

(a) Find the sample mean x.

Sum divided by the number of students. So

$x = \frac{5*0 + 9*1 + 5*2 + 5*3 + 1*4}{5 + 9 + 5 + 5 + 1} = \frac{38}{25} = 1.52$

(b) Find the approximate sample standard deviation, s.

Standard deviation of the sample.

Square root of the sum of the squares of the values subtracted from the mean, divided by the sample size subtracted by 1. So

$s = \sqrt{\frac{5*(0-1.52)^2 + 9*(1-1.52)^2 + 5*(2-1.52)^2 + 5*(3-1.52)^2 + 1*(4-1.52)^2}{24}} = \sqrt{\frac{32.24}{24}} = 1.16$

3 0

3 years ago

O. Find the distance between P (10,-7) and Q (7,- 10). Leave your answer in radical form.

mr Goodwill [35]

Answer:

$\sqrt{18}$ or $3\sqrt{2}$ units.

Step-by-step explanation:

To find the distance between two points, we can use the Distance Formula.

Distance Formula: $d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$

Given:

P (10, -7) ⇒ x₁ = 10, y₁ = -7

Q (7, -10) ⇒ x₂ = 7, y₂ = -10

Substitute the given values into the formula and simplify.

$\\\implies d=\sqrt{\bold{(7-10)}^2+\bold{(-10-(-7))}^2}\\\\\implies d=\sqrt{\bold{(-3)}^2+\bold{(-10+7)}^2}\\\\\implies d=\sqrt{9+\bold{(-3)}^2}\\\\\implies d=\sqrt{\bold{9+9}}\\\\\implies d=\sqrt{\bold{18}}\\\\\implies d=\sqrt{\bold{9}\times2}\\\\\implies d=3\sqrt{2}$

The distance between points P and Q is $\sqrt{18}$ or $3\sqrt{2}$ units.

Learn more here:

brainly.com/question/27991769

brainly.com/question/21095661

3 0

2 years ago

Read 2 more answers

A basketball player shoots a free throw in a game. The quadratic expression models the height of the ball, in feet, where t is t

Temka [501]

Answer:

the initial height of ball when the player releases it

Step-by-step explanation:

A basketball player shoots a free throw in a game. The quadratic expression models the height of the ball, in feet, where t is the time, in seconds.

y= -16t^2 + 25t+7

Given equation is in the form of

y= -16x^2 + V t + h

Where V represents the initial velocity and h represents the initial height of the ball

Now we compare our equation with the general equation

We have 7 in the place of h

So , 7 is the initial height of the ball

Answer is 7 is the initial height of ball when the player releases it

5 0

3 years ago

Read 2 more answers

Cos (pi/2 -x) = sin x is this true or false?

Ksenya-84 [330]

The above statement is true meaning cos(π/₂-x)=sin(x)

Step-by-step explanation:

We know that sine and cosine function are mutual cofunctions.

Hence this would mean that these two functions are complimentary of each other meaning cos(π/₂-x) = sin(x)

This can be verified mathematically by assuming “x” as 30°

Hence Cos (π/₂-30°) = cos 60°= 0.5 (from trigonometric table values)

Similarly Sin 30°= 0.5 (from trigonometric table values)

This can be proved through using the formula

Cos(A-B)= Cos A.Cos B + Sin A.Sin B

Here A=90° and b=x°

Putting the values we get (it is to be remembered that cos 90°=0 and sin 90°=1)

Cos 90°.cos x+ sin 90.sin x

0+sinx= sinx

Hence it is proved that cos(π/₂-x)=sin(x)

7 0

3 years ago

What is the equation of the line that passes through the point (6,−7) and has a slope of -3/2

baherus [9]

Answer:

y = -3/2x + 2

Step-by-step explanation:

slope-line equation : y = mx + b

slope is -3/2

Let's find the y-intercept using (6, -7)

y = mx + b

-7 = -3/2(6) + b

-7 = -18/2 + b

-7 = -9 + b

+9 +9

-----------------------

2 = b

So, y = -3/2x + 2 is your equation.

8 0

2 years ago