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TiliK225 [7]
2 years ago
15

Forty five children attend a preschool. The number of two year olds is one half of the number of three year old's. The number of

four year olds is the same number as the number of three year old's. How many two year old's are there? How many three year old's are there? How many four year old's are there?
Mathematics
1 answer:
Maurinko [17]2 years ago
5 0

To put this into an equation, we can make x the amount of two year old's there are.

x+2x+2x=45

5x=45

x=9

9 two year old's, 18 three year old's, and 18 four year old's.

You might be interested in
The function f(x) = xπ−−√ gives the diameter, in inches, of a proposed spherical sculpture with a surface area of x square inche
natka813 [3]

Answer:

The average rate of change of f(x) = 3.14 inches⁻¹

The change in f(x) = 49.32 in

Step-by-step explanation:

The surface area of the spherical sculpture = x and its diameter f(x) = πx.

The average rate of change of f(x) as x changes is df(x)/dx = π = 3.14

Now the change in diameter Δf(x) = df(x) = (df(x)/dx)dx = πdx  

dx = Δx = 28.3 in² - 12.6 in² = 15.7 in²

df(x) = π × 15.7 = 49.32 in

3 0
2 years ago
A manufacturer of paper coffee cups would like to estimate the proportion of cups that are defective (tears, broken seems, etc.)
Maksim231197 [3]

Answer:

a

  The 95% confidence interval is  0.0503  <   p < 0.1297

b

The sample proportion is  \r p =  0.09

c

The critical value is  Z_{\frac{\alpha }{2} } =  1.96

d

 The standard error is  SE   =0.020

Step-by-step explanation:

From the question we are told that

   The  sample size is  n =  200

     The number of defective is  k =  18

The null hypothesis is  H_o  :  p  =  0.08

The  alternative hypothesis is  H_a  :  p > 0.08

Generally the sample proportion is mathematically evaluated as

            \r p =  \frac{18}{200}

            \r p =  0.09

Given that the confidence level is  95% then the level  of significance is mathematically evaluated as

        \alpha  =  100 -  95

        \alpha  =  5\%

        \alpha  =  0.05

Next we obtain the critical value of  \frac{ \alpha }{2} from the normal distribution table, the value is  

        Z_{\frac{\alpha }{2} } =  1.96

Generally the standard of error is mathematically represented as

          SE   =  \sqrt{\frac{\r p (1 -  \r p)}{n} }

substituting values

         SE   =  \sqrt{\frac{0.09  (1 -  0.09)}{200} }

        SE   =0.020

The  margin of error is  

       E =  Z_{\frac{ \alpha }{2} }  * SE

=>    E =  1.96  *  0.020

=>   E =  0.0397

The  95% confidence interval is mathematically represented as

     \r p  -  E  <  \mu <  p <  \r p  + E

=>   0.09 - 0.0397  <  \mu <  p < 0.09 + 0.0397

=>  0.0503  <   p < 0.1297

7 0
2 years ago
Dan is fourteen years older than Marge. Eight years ago, Dan was three times as old as Marge. Find their present age.
34kurt

Answer:

<u>Marge's</u> present age = 14 ; <u>Dan's</u> present age = 29

Step-by-step explanation:

  • Present age

Let Marge's present age be = M

Dan's present age [D] : 14 years elder than Marge = M + 14

  • 8 years ago  

Marge Age = M - 8

Dan's Age = D - 8 = (M + 14) - 8 = M + 6  

{Given} : Dan's age = 3 times Marge's age

M + 6 = 3 (M - 8)

M + 6 = 3M - 24

6 + 24 = 3M - M

30 = 2M

M = 30/2

M = 15 [Marge's present age]

Dan's present age [D] = M + 14 = 29

5 0
2 years ago
Mr. Dennis travels 27.2 miles to work each day.
galina1969 [7]

Answer:

g5v869v96r9v

rc55vdr66ves5c5sxStep-by-step explanation:

6 0
2 years ago
Round 21,253 to the nearest hundred.
Mazyrski [523]

Answer:

Hey there! The answer to your question is 21,300

Step-by-step explanation:

If we look at the 253 it is most close to 300 not 200 so the answer will be 21,300

Hope that helps!

By: xBrainly

6 0
2 years ago
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