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2 years ago

PLEASE HELP ASAP I always give brainliests!

Mathematics

1 answer:

nlexa [21]2 years ago

7 0

first to find average age add all the ages divide by number of ages 4

5+4=9

9+6=15

15+39=54

54/4=13.5

For standard deviation find the mean/average

13.5

then subtract the mean from each number/age

5-13.5=-8.5

4-13.5=-9.5

6-13.5=-7.5

39-13.5=25.5

then square each number

-8.5^2=-72.25

-9.5^2=-90.25

-7.5^2=-56.25

25.5^2=650.25

then find the mean/average of the new numbers

-72.25+-90.25+-56.25+650.25=431.5

431.5/4=107.85

then take the square root of the new mean/average

$\sqrt{ 107.875}\\10.38628903...$

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A real estate agent has 19 properties that she shows. She feels that there is a 30% chance of selling any one property during a

netineya [11]

Answer:

$P(X \geq 5)=1-P(X$

We can find the individual probabilities:

$P(X=0)=(19C0)(0.3)^0 (1-0.3)^{19-0}=0.00114$

$P(X=1)=(19C1)(0.3)^1 (1-0.3)^{19-1}=0.0092$

$P(X=2)=(19C2)(0.3)^2 (1-0.3)^{19-2}=0.0358$

$P(X=3)=(19C3)(0.3)^3 (1-0.3)^{19-3}=0.0869$

$P(X=4)=(19C4)(0.3)^4 (1-0.3)^{19-4}=0.1491$

And replacing we got:

$P(X \geq 5) = 1-[0.00114+0.009282+0.0358+0.0869+0.149]= 0.7178$

Step-by-step explanation:

Previous concepts

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

Solution to the problem

Let X the random variable of interest, on this case we now that:

$X \sim Binom(n=19, p=0.3)$

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

$nCx=\frac{n!}{(n-x)! x!}$

And we want to find this probability:

$P(X \geq 5)$

And we can use the complement rule:

$P(X \geq 5)=1-P(X$

We can find the individual probabilities:

$P(X=0)=(19C0)(0.3)^0 (1-0.3)^{19-0}=0.00114$

$P(X=1)=(19C1)(0.3)^1 (1-0.3)^{19-1}=0.0092$

$P(X=2)=(19C2)(0.3)^2 (1-0.3)^{19-2}=0.0358$

$P(X=3)=(19C3)(0.3)^3 (1-0.3)^{19-3}=0.0869$

$P(X=4)=(19C4)(0.3)^4 (1-0.3)^{19-4}=0.1491$

And replacing we got:

$P(X \geq 5) = 1-[0.00114+0.009282+0.0358+0.0869+0.149]= 0.7178$

4 0

3 years ago

Anyone know this? Ill give brainliest if right pls help ^^

Varvara68 [4.7K]

Answer:

Female=14 male=6

Step-by-step explanation:

Oof this toke long I understand it now, for yesterday you gotta do 6+6+6+6+6=30 this is the male and so you add 14 to 30=44, now comes the important part of solving this problem. For today you gotta add 4 men and 4 women so you do 6+6+6+6=24 now 14+14+14+14=56 and if you add 56+24=80 .

4 0

3 years ago

In a survey 9 out of 15 named math as their favorite class. express this rate as a decimal

ZanzabumX [31]

0.6 is 9/15 as a decimal.

3 0

3 years ago

The ratio of girls to boys in Mr. Smith's homeroom is 3:4. The ratio in Mr. Smith's homeroom to students in the whole 7th grade

Leno4ka [110]

3:4 = G:B

1:5 = Mr. Smith's class: 7th Grade

2:7= 7th: Middle school

12 girls = 3 units

1 unit = 12/3= 4

Boys = 4x4= 16

Whole class = 28 students

Class : Grade = 1:5 7 = number of units in Mr. Smith's class

28 = 1 unit

5 units= 28x5= 140 There are 140 kids in the grade

140 = 2 units

1 unit = 140/2= 70

70x7=490

There are 490 students in the whole grade

6 0

2 years ago

The length of a rectangle is 12 in. and the perimeter is 56 in. find the width of the rectangle

pentagon [3]

The perimeter p of the rectangle with length l and width w is:
p = 2l + 2w
that is, two times its length and two times its width, lets solve for the width w and substitute known data:
p = 2l + 2w
2w = p - 2l
w = (p - 2l)/2
w = (56 - (2*12))/2
w = (56 - 24)/2
w = 32/2
w = 16
therefore the width of the rectangle is 16 in

8 0

3 years ago