Find two numbers with a sum of 20 and a difference of 14.

Wewaii [24]

I believe it’s 180 or something to do with that

3 0

2 years ago

A simple random sample of size nequals10 is obtained from a population with muequals68 and sigmaequals15. (a) What must be true

valentina_108 [34]

Answer:

(a) The distribution of the sample mean ( $\bar x$ ) is N (68, 4.74²).

(b) The value of $P(\bar X$ is 0.7642.

(c) The value of $P(\bar X\geq 69.1)$ is 0.3670.

Step-by-step explanation:

A random sample of size n = 10 is selected from a population.

Let the population be made up of the random variable X.

The mean and standard deviation of X are:

$\mu=68\\\sigma=15$

(a)

According to the Central Limit Theorem if we have a population with mean μ and standard deviation σ and we take appropriately huge random samples (n ≥ 30) from the population with replacement, then the distribution of the sample mean will be approximately normally distributed.

Since the sample selected is not large, i.e. n = 10 < 30, for the distribution of the sample mean will be approximately normally distributed, the population from which the sample is selected must be normally distributed.

Then, the mean of the distribution of the sample mean is given by,

$\mu_{\bar x}=\mu=68$

And the standard deviation of the distribution of the sample mean is given by,

$\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}=\frac{15}{\sqrt{10}}=4.74$

Thus, the distribution of the sample mean ( $\bar x$ ) is N (68, 4.74²).

(b)

Compute the value of $P(\bar X$ as follows:

$P(\bar X$

$=P(Z$

*Use a z-table for the probability.

Thus, the value of $P(\bar X$ is 0.7642.

(c)

Compute the value of $P(\bar X\geq 69.1)$ as follows:

Apply continuity correction as follows:

$P(\bar X\geq 69.1)=P(\bar X> 69.1+0.5)$

$=P(\bar X>69.6)$

$=P(\frac{\bar X-\mu_{\bar x}}{\sigma_{\bar x}}>\frac{69.6-68}{4.74})$

$=P(Z>0.34)\\=1-P(Z$

Thus, the value of $P(\bar X\geq 69.1)$ is 0.3670.

7 0

3 years ago

Dafna1 [17]

The related number sentence that shows the commutative property addition for the equation 3+ 9 + 12 is 9 + 3 = 12

Please take note, the commutative property of addition is
a + b = c
b + a = c
a + b = b + a

Commutative originates from the word move around or commute, therefore, commutative property refers to the act of moving stuff around. In addition, the rule is a + b = b + a; wherein from the example above, means 9 + 3 = 3 + 9. They want to say that the computation uses the Commutative Property, if at any time, a computation depends on moving stuff around

6 0

3 years ago

What is the solution for this set of equation (2r-3)-4=37

Alex777 [14]

Answer:

(2r-3)-4=37

or,(2r-3)=37+4

or,2r-3=41

or,2r=41+3

or,2r=44

or, r= 44/2

hence , r= 22

5 0

3 years ago

What would my answer be?

Svetllana [295]

Since triangle is isosceles, that means that unknown angles are equal. 180-72=108
108:2=54
So you’re answer would be: 54 degrees.

4 0

3 years ago