All categories

3 years ago

Can someone help I need this asap

Mathematics

1 answer:

balu736 [363]3 years ago

4 0

Answer:

Step-by-step explanation:

Total number of students =100

Number who bought pop corn = 62

Number who bought drinks = 47

Number who bought both =38

Hence number who did not purchase anything = 100-(62+47-38)

=29

Prob that students buys a drink = 47/100 = 0.47

PROB THAT THE student buys a drink/he purchsaed pop corn

= Number for both/number of pop corn

=38/62 =0.613

P(buying pop corn) = 0.62 and P(drink) = 0.47

Product of these = 0.62*0.37=0.2356

Thus we find product is not equal to Prob of purchsing both

Hence cannot be independent

You might be interested in

The measurenicnt of the circumference of a circle is found to be 56 centimeters. The possible error in measuring the circumferen

BartSMP [9]

Answer:

(a) Approximate the percent error in computing the area of the circle: 4.5%

(b) Estimate the maximum allowable percent error in measuring the circumference if the error in computing the area cannot exceed 3%: 0.6 cm

Step-by-step explanation:

(a)

First we need to calculate the radius from the circumference:

$c=2\pi r\\r=\frac{c}{2\pi } \\c=8.9 cm$

I leave only one decimal as we need to keep significative figures

Now we proceed to calculate the error for the radius:

$\Delta r=\frac{dt}{dc} \Delta c\\\\\frac{dt}{dc} = \frac{1}{2 \pi } \\\\\Delta r=\frac{1}{2 \pi } (1.2)\\\\\Delta r= 0.2 cm$

$r = 8.9 \pm 0.2 cm$

Again only one decimal because the significative figures

Now that we have the radius, we can calculate the area and the error:

$A=\pi r^{2}\\A=249 cm^{2}$

Then we calculate the error:

$\Delta A= (\frac{dA}{dr} ) \Delta r\\\\\Delta A= 2\pi r \Delta r\\\\\Delta A= 11.2 cm^{2}$

$A=249 \pm 11.2 cm^{2}$

Now we proceed to calculate the percent error:

$\%e =\frac{\Delta A}{A} *100\\\\\%e =\frac{11.2}{249} *100\\\\\%e =4.5\%$

(b)

With the previous values and equations, now we set our error in 3%, so we just go back changing the values:

$\%e =\frac{\Delta A}{A} *100\\\\3\%=\frac{\Delta A}{249} *100\\\\\Delta A =7.5 cm^{2}$

Now we calculate the error for the radius:

$\Delta r= \frac{\Delta A}{2 \pi r}\\\\\Delta r= \frac{7.5}{2 \pi 8.9}\\\\\Delta r= 0.1 cm$

Now we proceed with the error for the circumference:

$\Delta c= \frac{\Delta r}{\frac{1}{2\pi }} = 2\pi \Delta r\\\\\Delta c= 2\pi 0.1\\\\\Delta c= 0.6 cm$

5 0

3 years ago

Verify this cofunction identity by using the difference identity for cosine. Show your work! cos⁡(π/2-θ)=sinθ

taurus [48]

Cos(A-B) = cosAcosB + sinAsinB

cos(π/2 - θ) = cos(π/2)cosθ + sin(π/2)sinθ

π/2 = 90°
cos(π/2) = cos90° = 0. sin(π/2) = sin90° = 1

cos(π/2 - θ) = cos(π/2)cosθ + sin(π/2)sinθ

= 0*cosθ + 1*sinθ = sinθ

Therefore cos(π/2 - θ) = sinθ

QED

8 0

3 years ago

The sum of two numbers is -18. If the first number is 10, which equation represents this situation, and what is the second numbe

ki77a [65]

Don’t know if there’s much of an equation for it, but I guess the best way to write it out is 10 + x = -18. Then, you would subtract the 10 from both sides in order to isolate the x. So then you’re left with x = -28. So -28 is your answer.

8 0

3 years ago

To paint a house, a painting company charges a flat rate of $500 for supplies, plus $50 for each hour of labor.

sattari [20]

Answer:

50x20=1000+500= 1500

50x50=2500+500=3000

Step-by-step explanation:

7 0

2 years ago

On a coordinate plane, a line has points (negative 2, negative 4) and (4, 2). Point P is at (0, 4). Which points lie on the line

NikAS [45]