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2 years ago

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in the 9th grade, 7 of every 10 students is a girl. if there are 200 students in the 9th grade, how many of the students are gir

ls

2 answers:

lidiya [134]2 years ago

5 0

I’m pretty sure 140 :)

zubka84 [21]2 years ago

4 0

Ratio of girls = 7/10

So, no. of girls = 200 × 7/10 = 20×7 = 140

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Please help! question is in the pic

steposvetlana [31]

Answer: 2 + 1 = 3 2 x 1 =2

Step-by-step explanation: + 7 = 7

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2 years ago

Mila and Ava play a number game. Mila gives Ava a number and she does three computations:

Lady bird [3.3K]

Answer:

Step-by-step explanation:

(x-5)2+8 = 92

2x-10+8 = 92

2x = 94

x = 47

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2 years ago

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f(x) = 3 cos(x) 0 ≤ x ≤ 3π/4 evaluate the Riemann sum with n = 6, taking the sample points to be left endpoints. (Round your ans

Kruka [31]

Answer:

$\int_{0}^{\frac{3 \pi}{4}}3 \cos{\left(x \right)}\ dx\approx 3.099558$

Step-by-step explanation:

We want to find the Riemann sum for $\int_{0}^{\frac{3 \pi}{4}}3 \cos{\left(x \right)}\ dx$ with n = 6, using left endpoints.

The Left Riemann Sum uses the left endpoints of a sub-interval:

$\int_{a}^{b}f(x)dx\approx\Delta{x}\left(f(x_0)+f(x_1)+2f(x_2)+...+f(x_{n-2})+f(x_{n-1})\right)$

where $\Delta{x}=\frac{b-a}{n}$ .

Step 1: Find $\Delta{x}$

We have that $a=0, b=\frac{3\pi }{4}, n=6$

Therefore, $\Delta{x}=\frac{\frac{3 \pi}{4}-0}{6}=\frac{\pi}{8}$

Step 2: Divide the interval $\left[0,\frac{3 \pi}{4}\right]$ into n = 6 sub-intervals of length $\Delta{x}=\frac{\pi}{8}$

$a=\left[0, \frac{\pi}{8}\right], \left[\frac{\pi}{8}, \frac{\pi}{4}\right], \left[\frac{\pi}{4}, \frac{3 \pi}{8}\right], \left[\frac{3 \pi}{8}, \frac{\pi}{2}\right], \left[\frac{\pi}{2}, \frac{5 \pi}{8}\right], \left[\frac{5 \pi}{8}, \frac{3 \pi}{4}\right]=b$

Step 3: Evaluate the function at the left endpoints

$f\left(x_{0}\right)=f(a)=f\left(0\right)=3=3$

$f\left(x_{1}\right)=f\left(\frac{\pi}{8}\right)=3 \sqrt{\frac{\sqrt{2}}{4} + \frac{1}{2}}=2.77163859753386$

$f\left(x_{2}\right)=f\left(\frac{\pi}{4}\right)=\frac{3 \sqrt{2}}{2}=2.12132034355964$

$f\left(x_{3}\right)=f\left(\frac{3 \pi}{8}\right)=3 \sqrt{\frac{1}{2} - \frac{\sqrt{2}}{4}}=1.14805029709527$

$f\left(x_{4}\right)=f\left(\frac{\pi}{2}\right)=0=0$

$f\left(x_{5}\right)=f\left(\frac{5 \pi}{8}\right)=- 3 \sqrt{\frac{1}{2} - \frac{\sqrt{2}}{4}}=-1.14805029709527$

Step 4: Apply the Left Riemann Sum formula

$\frac{\pi}{8}(3+2.77163859753386+2.12132034355964+1.14805029709527+0-1.14805029709527)=3.09955772805315$

$\int_{0}^{\frac{3 \pi}{4}}3 \cos{\left(x \right)}\ dx\approx 3.099558$

5 0

2 years ago

5. a) Which figure is the mapping diagram of the relation

Viefleur [7K]

Answer:

b, since the others have the input and output on the wrong sides

7 0

2 years ago

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Trucks in a delivery fleet travel a mean of 110 miles per day with a standard deviation of 38 miles per day. The mileage per day

Montano1993 [528]

Answer: 0.1824

Step-by-step explanation:

Given : The mileage per day is distributed normally with

Mean : $\mu=110\text{ miles per day}$

Standard deviation : $\sigma=38\text{ miles per day}$

Let X be the random variable that represents the distance traveled by truck in one day .

Now, calculate the z-score :-

$z=\dfrac{x-\mu}{\sigma}$

For x= 132 miles per day.

$z=\dfrac{132-110}{38}\approx0.58$

For x= 159 miles per day.

$z=\dfrac{159-110}{38}\approx1.29$

Now by using standard normal distribution table, the probability that a truck drives between 132 and 159 miles in a day will be :-

$P(132$

Hence, the probability that a truck drives between 132 and 159 miles in a day =0.1824

6 0

2 years ago