Only answer if known and please show work

9 out of 20 students will attend the Worldwide Day of Play at RMS what percentage of students will not attend

EastWind [94]

U do 4/20 = p/100 then u cross multiply the 4 with 100 getting u 400, then divide the 400 by 20, giving u the answer of 20%

8 0

3 years ago

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The daily average temperature in Santiago, Chile, varies over time in a periodic way that can be modeled approximately by a trig

natali 33 [55]

Answer:

a) the trigonometric function is;

$y = 7.5 sin ( \frac{2 \pi}{365}t + \frac{337 \pi}{730})+ 21.5$

b) $y = 28.36^0 \ C$ ( to two decimal places)

Step-by-step explanation:

This data can be represented by the sinusoidal function of the form :

$\mathbf{y = A sin (Bt -C)+D}$

where A = amplitude and which can be determined via the formula:

$A = \dfrac{largest \ temperature - lowest \ temperature}{2}$

$A = \dfrac{29-14}{2}$

$A = \dfrac{15}{2}$

A = 7.5° C

where B = the frequency;

Since the data covers a period of 3 days ; then $\dfrac{2 \pi}{B } =365$

$B = \dfrac{2 \pi}{365}$ ( where 365 is the time period )

The vertical shift is found by the equation D;

D = $\frac{largest \ temperature + lowest \ temperature}{2}$

D = $\frac{29+14}{2}$

D = 21.5

Replacing the values of A ; B and D into the above sinusoidal function; we have :

$y = 7.5 sin (\frac{2 \pi}{365}t -C) + 21.5$

From the question; when it is 7th of the year ( i.e January 7);

t = 7 and the temperature (y) = 29° C

replacing that too into the above equation; we have:

$29= 7.5 sin (\frac{2 \pi}{365}*7 -C) + 21.5$

$29= 7.5 sin (\frac{14 \pi}{365} -C) + 21.5$

$\frac{29-21.5}{7.5}= sin (\frac{14 \pi}{365} -C)$

$1= sin (\frac{14 \pi}{365} -C)$

$sin^{-1}(1)= (\frac{14 \pi}{365} -C)$

$\frac{\pi}{2}= (\frac{14 \pi}{365} -C)$

$C= (\frac{14 \pi}{365} -\frac{\pi}{2})$

$C= (\frac{28 \pi- 365 \pi}{730} )$

$C= \frac{-337 \pi}{730}$

Thus; the trigonometric function is;

$y = 7.5 sin ( \frac{2 \pi}{365}t + \frac{337 \pi}{730})+ 21.5$

Similarly; to determine the temperature o Jan 31; i.e when t= 31 ; we have :

$y = 7.5 sin ( \frac{2 \pi}{365}*31+ \frac{337 \pi}{730})+ 21.5$

$y = 7.5 sin ( \frac{62 \pi}{365}+ \frac{337 \pi}{730})+ 21.5$

$y = 7.5 sin ( \frac{124 \pi+ 337 \pi }{730})+ 21.5$

$y = 7.5 sin ( \frac{461 \pi }{730})+ 21.5$

$y = 7.5 *( 0.915)+ 21.5$

$y = 6.8689+ 21.5$

$y = 28.36^0 \ C$ ( to two decimal places)

7 0

3 years ago

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Alex invests his money in an account paying 2% interest compounded semiannually. What is the effective annual yield on this acco

Travka [436]

Answer: 2.01%.

Step-by-step explanation:

Suppose Alex invests $1 into the account for one year. The formula is A=P0⋅(1+rk)N⋅k with P0=$1. We know that r=0.02 and k=2 compounding periods per year. Now, N=1 year. Substituting the values we have A=$1⋅(1+0.022)2=$1.0201. Now, to calculate the effective annual yield, we will use the formula rEFF=A−P0P0. rEFF=1.0201−11=0.0201 or 2.01%. When rounded to two decimals, rEFF=2.01%. However, do not include the % in your answer.

3 0

2 years ago

Write down the general equation of the normal distribution

Talja [164]

The following is the plot of the normal percent point function. where \phi is the cumulative distribution function of the standard normal distribution and Φ is the probability density function of the standard normal distribution.

8 0

2 years ago

Find the distance between the points (4,3) and (-1,4) round answer to the nearest tenth

scZoUnD [109]

Answer:

The distance between those points rounded to the nearest tenth is 5.1

Step-by-step explanation:

1. (x2-x1) = (-1 - 4) = -5

2. (y2-y1) = (4 - 3) = 1

3. (-5^)2 + (1)^2 = 25 + 1 = 26

4. √26 = √26

5. 5.099 ---> Rounded to the nearest tenth = 5.1

5 0

2 years ago