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1 year ago

What is the best estimate for 7.8 x 37.86? A. 46 B. 50 C. 300 D. 400

Mathematics

2 answers:

lana66690 [7]1 year ago

8 0

I think it’s C since it’s 295.308

pogonyaev1 year ago

4 0

Answer:

300

Step-by-step explanation:

7.8 x 37.86 = 295.308

round it to the nearest hundred which

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Underage drinking, Part II: We learned in Exercise 3.25 that about 69.7% of 18-20 year olds consumed alcoholic beverages in 2008

Murrr4er [49]

Answer:

Step-by-step explanation:

Hello!

The variable of interest is

X: number of 18-20-year-olds that consume alcoholic beverages in a sample of 50.

The proportion of underage people that drinks are known to be p= 0.697

This variable is discrete. This experiment has two possible outcomes success or failure, we will call "success" each time we encounter an underage individual that consumes alcohol and "failure" will be counting an underage that does not consume alcohol. The number of repetitions of the trial is fixed n= 50. All randomly selected underage individuals are independent and the probability of success is constant trough the whole experiment p=0.697.

Then we can say that this variable has a binomial distribution and we will use that distribution to do the calculations.

a. Under a binomial distribution, the expected value is calculated as:

E(X)= n*p= 50*0.697= 34.85.

The variance of a binomial distribution is:

V(X)= n*p*(1-p)= 50*0.697*0.303= 10.55955

And the standard deviation is the square root of the variance:

√V(X)= 3.2495 ≅ 3.25

b. To know how rare the value 45, you have to see how distant it is concerning the expected value. For this you have to subtract the expected value and divide it by the standard deviation:

[X-E(X)]/√V(X)

(45-34.85)/3.25= 3.12

The value X=45 is 3.12 standard deviations above the mean, which means that it would be rare to find 45 people or more than consumed alcohol.

c. P(X≥45) = 1 - P(X<45)= 1 - P(X≤44)= 1 - 0.9994= 0.0006

I hope it helps!

8 0

1 year ago

What is the ratio of the area of sector ABC to the area of sector DBE?

shusha [124]

We have to find the" ratio of the area of sector ABC to the area of sector DBE".

Now,

the general formula for the area of sector is

Area of sector= 1/2 r²θ

where r is the radius and θ is the central angle in radian.

180°= π rad

1° = π/180 rad

For sector ABC, area= 1/2 (2r)²(β°)

= 1/2 *4r²*(π/180 β)

= 2r²(π/180 β)

For sector DBE, area= 1/2 (r)²(3β°)

= 1/2 *r²*3(π/180 β)

= 3/2 r²(π/180 β)

Now ratio,

Area of sector ABC/Area of sector DBE = $\frac{2r^{2}*\ \frac{\pi}{180} beta}{3/2 r^{2}*\ \frac{\pi}{180}beta}$

= 4/3

7 0

2 years ago

Read 2 more answers

Under ideal conditions a certain bacteria population is known to double every three hours. Suppose that there are initially 100

lara [203]

Answer:

the estimation of the size of the population after 20 hours is 10159

Step-by-step explanation:

The computation of the size of the population after 20, hours is shown below;

= 100 2^(20 by 3)

= 10159.36

If we divide 20 by 3 so it would give 6.66 that lies between 6 and 7

So the estimation of the size of the population after 20 hours is 10159

hence, the same is relevant

3 0

1 year ago

Read 2 more answers

Between 1896—when the Dow Jones index was created— and 2012, the index rose in 65% of the years. Based on this information, and

forsale [732]

Answer:

a) P(x) = 0.67

b) P(y) = 0.67

c) P(x=4) = 0.3325

d) P( x = 0 ) = 0.0039

e) The fact that the rise and fall of the stock market relies on market sentiments violates independence used in Binomial distribution and the years are independent

Step-by-step explanation:

A) The probability that the stock market will rise next year = P(x) = 0.67

assuming next year to be X

B) Probability that the stock market will rise the year after next year

= P(y) = 0.67 and this is because the probability is independent of that of the previous years

C) Probability that the stock market will rise in four of the next five years

= P(x=4) = 0.3325

D) probability that the stock market will rise in none of the next five years

= P( x = 0 ) = 0.0039

E) The fact that the rise and fall of the stock market relies on market sentiments violates independence used in Binomial distribution and the years are independent