All categories

3 years ago

The arithmetic average of 10 numbers -2, -5,-2, 5, x , -3 10, 3, 8, -10 is 8 find x

Mathematics

1 answer:

Anvisha [2.4K]3 years ago

3 0

Arithmetic average = Sum of all the numbers /Total numbers

SO arithmetic average= {(-2)+(-5)+(-2)+(5)+(x)+(-3)+(10)+(3)+(8)+(-10)} / 10

={4x} /10

=0.4 x

As Given Arithmetic average= 8

so 0.4x =8

Dividing 0.4 Both sides

0.4x/0.4 = 8/0.4

x= 20

You might be interested in

The quotient of a number and four decreased by ten is two. what is the number

Ghella [55]

(x÷4)−10=2

<span> x/4= 12

x= 12*4

x= 48</span>

6 0

4 years ago

A research team conducted a study showing that approximately 15% of all businessmen who wear ties wear them so tightly that they

Helen [10]

Answer:

a) 0.913

b) 0.397

c) 0.087

Step-by-step explanation:

We are given the following information:

We treat wearing tie too tight as a success.

P(Tight tie) = 15% = 0.15

Then the number of businessmen follows a binomial distribution, where

$P(X=x) = \binom{n}{x}.p^x.(1-p)^{n-x}$

where n is the total number of observations, x is the number of success, p is the probability of success.

Now, we are given n = 15

We have to evaluate:

a) at least one tie is too tight

$P(x \geq 1) = P(x = 1) +....+ P(x = 15)\\=1 - P(x = 0)\\= 1 - \binom{15}{0}(0.15)^0(1-0.15)^{15}\\=1 - 0.087\\= 0.913$

b) more than two ties are too tight

$P(x > 2) = P(x = 3) +....+ P(x = 15)\\=1 - P(x = 0) - P(x=1) - P(x=2)\\= 1 - \binom{15}{0}(0.15)^0(1-0.15)^{15}-\binom{15}{1}(0.15)^1(1-0.15)^{14}-\binom{15}{0}(0.15)^2(1-0.15)^{13}\\=1 - 0.087 - 0.231 - 0.285\\= 0.397$

c) no tie is too tight

$P(x = 0)\\=\binom{15}{0}(0.15)^0(1-0.15)^{15}\\=0.087$

d) at least 18 ties are not too tight

This probability cannot be evaluated as the number of success or the failures exceeds the number of trials given which is 15.

The probability is asked for 18 failures which cannot be evaluated.

8 0

4 years ago

the participants in a television quiz show are picked from a large pool of applicants with approximately equal numbers of men an

Nostrana [21]

Answer:

The probability of getting 2 or fewer women when 10 people are picked

P(x≤ 2) = $\frac{56}{1024} = 0.0546$

Step-by-step explanation:

The participants in a television quiz show are picked from a large pool of applicants with approximately equal numbers of men and women

That is probability of participants of television quiz of equal numbers of men and women that is 50 %of men and 50% of women.

p = 50/100 = 1/2

q = 1-p = 1 - 1/2 = 1/2

n =10

we will use binomial distribution $p(x =r) = n_{cr} p^{r} q^{n-r}$

The probability of getting 2 or fewer women when 10 people are picked

P(x≤ 2) = P(x=0)+P(x=1)+P(x=2)

= $10_{c0} \frac{1}{2} ^{0} (\frac{1}{2}) ^{10-0}+ 10_{c1} \frac{1}{2} ^{1} (\frac{1}{2}) ^{10-1 \\$ + $10_{c2} \frac{1}{2} ^{2} (\frac{1}{2}) ^{10-2$