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Andrei [34K]
3 years ago
15

Hi can you guys help me know how to explain this?

Mathematics
1 answer:
ludmilkaskok [199]3 years ago
6 0
10 x 25 = 250, well 20 x 25 is just double that, its 10 doubled x 25 so he probably just added it up. repeated addition really helps with times tables. 
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2. The Welcher Adult Intelligence Test Scale is composed of a number of subtests. On one subtest, the raw scores have a mean of
IgorC [24]

Answer:

a) 37.31 b) 42.70 c) 0.57 d) 0.09

Step-by-step explaanation:

We are regarding a normal distribution with a mean of 35 and a standard deviation of 6, i.e., \mu = 35 and \sigma = 6. We know that the probability density function for a normal distribution with a mean of \mu and a standard deviation of \sigma is given by

f(x) = \frac{1}{\sqrt{2\pi}\sigma}\exp[-\frac{(x-\mu)^{2}}{2\sigma^{2}}]

in this case we have

f(x) = \frac{1}{\sqrt{2\pi}6}\exp[-\frac{(x-35)^{2}}{2(6^{2})}]

Let X be the random variable that represents a row score, we find the values we are seeking in the following way

a)  we are looking for a number x_{0} such that

P(X\leq x_{0}) = \int\limits^{x_{0}}_{-\infty} {f(x)} \, dx = 0.65, this number is x_{0}=37.31

you can find this answer using the R statistical programming languange and the instruction qnorm(0.65, mean = 35, sd = 6)

b) we are looking for a number  x_{1} such that

P(X\leq x_{1}) = \int\limits^{x_{1}}_{-\infty} {f(x)} \, dx = 0.9, this number is x_{1}=42.70

you can find this answer using the R statistical programming languange and the instruction qnorm(0.9, mean = 35, sd = 6)

c) we find this probability as

P(28\leq X\leq 38)=\int\limits^{38}_{28} {f(x)} \, dx = 0.57

you can find this answer using the R statistical programming languange and the instruction pnorm(38, mean = 35, sd = 6) -pnorm(28, mean = 35, sd = 6)

d) we find this probability as

P(41\leq X\leq 44)=\int\limits^{44}_{41} {f(x)} \, dx = 0.09

you can find this answer using the R statistical programming languange and the instruction pnorm(44, mean = 35, sd = 6) -pnorm(41, mean = 35, sd = 6)

6 0
3 years ago
Read 2 more answers
20% of a restaurant customers order the chef’s special. 230 customers are anticipated to dine at the restaurant tonight. The sta
Serga [27]

Answer:

i don't knwo

Step-by-step explanation:

i

4 0
3 years ago
A 2b (3 a 2 + 4 ab 2 )
Gala2k [10]

Answer:

You should get 13

Step-by-step explanation:

3 0
3 years ago
If a graph shows the function y=3x what are the coordinates of the intercepts
vladimir2022 [97]

Answer:

graph{3x+5 [-10, 10, -5, 5]}

x

intercept:  

x

=

−

5

3

 

y

intercept:  

y

=

5

Explanation:

For a linear graph, the quickest way to sketch the function is to determine the  

x

and  

y

intercepts and draw a line between the two: this line is our graph.

Let's calculate the  

y

intercept first:

With any function,  

y

intercepts where  

x

=

0

.

Therefore, substituting  

x

=

0

into the equation, we get:

y

=

3

⋅

0

+

5

y

=

5

Therefore, the  

y

intercept cuts through the point (0,5)

Let's calculate the  

x

intercept next:

Recall that with any function:  

y

intercepts where  

x

=

0

.

The opposite is also true: with any function  

x

intercepts where  

y

=

0

.

If we substitute  

y

=

0

, we get:

0

=

3

x

+

5

Let's now rearrange and solve for  

x

to calculate the  

x

intercept.

−

5

=

3

x

 

−

5

3

=

x

Therefore, the  

x

intercept cuts through the point  

(

−

5

3

,

0

)

.

Now we have both the  

x

and  

y

intercepts, all we have to do is essentially plot both intercepts on a set of axis and draw a line between them

The graph of the function  

y

=

3

x

+

5

:

graph{3x+5 [-10, 10, -5, 5]}



3 0
3 years ago
What is the function to 5c+4=2 (c-5)
Vinvika [58]
To solve the function we proceed as follows:
5c+4=2(c-5)
opening the parentheses we get:
5c+4=2c-10
putting like terms together we get
5c-2c=-10-4
3c=-14
c=-14/3        
4 0
3 years ago
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