I need help with this

If 28% of students in College are near-sighted, the probability that in a randomly chosen group of 20 College students, exactly

cluponka [151]

Answer: (D) 16%

Step-by-step explanation:

Binomial probability formula :-

$P(x)=^nC_xp^x(1-p)^n-x$ , where n is the sample size , p is population proportion and P(x) is the probability of getting success in x trial.

Given : The proportion of students in College are near-sighted : p= 0.28

Sample size : n= 20

Then, the the probability that in a randomly chosen group of 20 College students, exactly 4 are near-sighted is given by :_

$P(x=4)=^{20}C_4(0.28)^4(1-0.28)^{20-4}\\\\=\dfrac{20!}{4!16!}(0.28)^4(0.72)^{16}\\\\=0.155326604912\approx0.16\%$

Hence, the probability that in a randomly chosen group of 20 College students, exactly 4 are near-sighted is closest to 16%.

7 0

3 years ago

The function c(x) = 3x − 4 determines how many cupcakes need to be purchased for a birthday party, where x is the number of kids

dezoksy [38]

The answer of d(c(x))=39. hope it will help you

6 0

3 years ago

Read 2 more answers

Yuri purchased 8 trees to have planted at his house. The store charged a delivery fee of $5 per tree.

cestrela7 [59]

Answer:

$16.

Step-by-step explanation:

Let t represent the cost of each tree.

We have been given that Yuri purchased 8 trees to have planted at his house. So the cost of 8 trees will be 8t.

We are also told that the store charged a delivery fee of $5 per tree. So the delivery charges of 8 trees will be $8\times \$5=\$40$

The total cost of purchasing 8 trees will be $8t+40$ .

Since the total cost of the trees including the delivery was $168, so we can get an equation as:

$8t+40=168$

$8t+40-40=168-40$

$8t=128$

Upon dividing both sides of our given equation by 8, we will get:

$\frac{8t}{8}=\frac{128}{8}$

$t=16$

Therefore, the cost of each tree is $16.

5 0

3 years ago

To estimate the mean number of text messages sent by cell-phone users, a researcher chooses a location on a college campus in th

igor_vitrenko [27]

Answer:

the answer is B :)

Step-by-step explanation:

edgen 2020

4 0

3 years ago

Given the tables for f & g below, find the following: x f ( x ) g ( x ) 0 9 7 1 4 8 2 3 6 3 5 1 4 7 5 5 1 2 6 6 0 7 0 4 8 2

d1i1m1o1n [39]

$\\(i)\\
\text{We know that the average rate of change of a function f(x) on inerval [a,b] is}\\
\\
f_{avg}=\frac{f(b)-f(a)}{b-a}\\
\\
\text{so using this the average rate of chang of g for x on interval }[3,7] \text{ is}\\
\\
g_{avg}=\frac{g(7)-g(3)}{7-3}\\
\\
=\frac{4-1}{4}\\
\\
=\frac{3}{4}\\
\\
\text{so average rate of change of g on interval [3,7] is }\frac{3}{4}$

$\\(ii)\\ \text{Average rate of chang of f for x on interval }[3,7] \text{ is}\\
\\
f_{avg}=\frac{f(7)-f(3)}{7-3}\\
\\
=\frac{0-5}{4}\\
\\
=\frac{-5}{4}\\
\\
\text{so average rate of change of g on interval [3,7] is }\frac{-5}{4}$

$\\(iii)\\
\text{Since g(4)=5, so we have}\\
\\
f(g(4))=f(5)\\
\\
\text{since the value of f is 1 at x=5. so }\\
\\
f(g(4))=f(5)=1\\
\\
\text{hence we have, }f(g(4))=$ 1

$\\(iv)\\
\text{Since f(3)=5, so we have}\\
\\
g(f(3))=g(5)\\
\\
\text{since the value of g is 2 at x=5. so }\\
\\
g(f(3))=g(5)=2\\
\\
\text{hence we have, }g(f(3))=$ 2

5 0

3 years ago