All categories

3 years ago

Please help me with number 4

Mathematics

2 answers:

AVprozaik [17]3 years ago

3 0

The answer is 105 students.

MariettaO [177]3 years ago

3 0

50 students = 7 have red hair

100 students = 14 have red hair

150 students = 21 have red hair

200 students = 28 have red hair

250 students = 35 have red hair

300 students = 42 have red hair

600 students = 84 have red hair

650 students = 91 have red hair

700 students = 98 have red hair

750 students = 105 have red hair

Therefore, around 105 students would have red hair out of all the students in the school.

You might be interested in

Need help on answering 20.

Reptile [31]

N=64.
32+64=100
64/8=8
sqrt (64+225)= sqrt (289) = positive and negative 17

8 0

2 years ago

Clara scored a 79 on her history test what grade does she have to get on her next test so she will have a average of a 83

Airida [17]

79 is 4 below 83 so her next grade needs to be 4 above in order to get an average of 83. The answer is 87.

6 0

3 years ago

-3 radical 2 times radical 3

topjm [15]

Answer:

-6

Step-by-step explanation:

$-3\sqrt{2}*\sqrt{2} = -3*2 = -6\\$

3 0

3 years ago

Determine whether a probability distribution is given. If a probability distribution is given, find its mean and standard deviat

drek231 [11]

Answer:

$E(X) = \sum_{i=1}^n X_i P(X_i) = 0*0.031 +1*0.156+ 2*0.313+3*0.313+ 4*0.156+ 5*0.031 = 2.5$

We can find the second moment given by:

$E(X^2) = \sum_{i=1}^n X^2_i P(X_i) = 0^2*0.031 +1^2*0.156+ 2^2*0.313+3^2*0.313+ 4^2*0.156+ 5^2*0.031 =7.496$

And we can calculate the variance with this formula:

$Var(X) =E(X^2) -[E(X)]^2 = 7.496 -(2.5)^2 = 1.246$

And the deviation is:

$Sd(X) = \sqrt{1.246}= 1.116$

Step-by-step explanation:

For this case we have the following probability distribution given:

X 0 1 2 3 4 5

P(X) 0.031 0.156 0.313 0.313 0.156 0.031

The expected value of a random variable X is the n-th moment about zero of a probability density function f(x) if X is continuous, or the weighted average for a discrete probability distribution, if X is discrete.

The variance of a random variable X represent the spread of the possible values of the variable. The variance of X is written as Var(X).

We can verify that:

$\sum_{i=1}^n P(X_i) = 1$

And $P(X_i) \geq 0, \forall x_i$

So then we have a probability distribution

We can calculate the expected value with the following formula:

$E(X) = \sum_{i=1}^n X_i P(X_i) = 0*0.031 +1*0.156+ 2*0.313+3*0.313+ 4*0.156+ 5*0.031 = 2.5$

We can find the second moment given by:

$E(X^2) = \sum_{i=1}^n X^2_i P(X_i) = 0^2*0.031 +1^2*0.156+ 2^2*0.313+3^2*0.313+ 4^2*0.156+ 5^2*0.031 =7.496$

And we can calculate the variance with this formula:

$Var(X) =E(X^2) -[E(X)]^2 = 7.496 -(2.5)^2 = 1.246$

And the deviation is:

$Sd(X) = \sqrt{1.246}= 1.116$

6 0

3 years ago

Two people decide to find the height of a tower they position themselves 25 feet apart in line with and on the same side of the

bonufazy [111]

1.477272727272727 I think this might be the answer.. devide 65 into 44 and youll get the answer

7 0

3 years ago