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3 years ago

Which inequality is true when x = 7?

Mathematics

2 answers:

vlabodo [156]3 years ago

7 0

The last one is true.

zlopas [31]3 years ago

4 0

Answer:

B,C,D

Step-by-step explanation:

−21<−3x

Answer: X<7

−5x>−35

Answer: x<7

The fourth also equals 7

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Whatcis 72/90 reduced

schepotkina [342]

472/90 reduced is 4/5

8 0

4 years ago

Read 2 more answers

The National Center for Education Statistics surveyed a random sample of 4400 college graduates about the lengths of time requir

Paha777 [63]

Answer:

95% confidence interval for the mean time required to earn a bachelor’s degree by all college students is [5.10 years , 5.20 years].

Step-by-step explanation:

We are given that the National Center for Education Statistics surveyed a random sample of 4400 college graduates about the lengths of time required to earn their bachelor’s degrees. The mean was 5.15 years and the standard deviation was 1.68 years respectively.

Firstly, the pivotal quantity for 95% confidence interval for the population mean is given by;

P.Q. = $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\bar X$ = sample mean time = 5.15 years

$\sigma$ = sample standard deviation = 1.68 years

n = sample of college graduates = 4400

$\mu$ = population mean time

Here for constructing 95% confidence interval we have used One-sample z test statistics although we are given sample standard deviation because the sample size is very large so at large sample values t distribution also follows normal.

So, 95% confidence interval for the population mean, $\mu$ is ;

P(-1.96 < N(0,1) < 1.96) = 0.95 {As the critical value of z at 2.5%

level of significance are -1.96 & 1.96}

P(-1.96 < $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ < 1.96) = 0.95

P( $-1.96 \times {\frac{\sigma}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $1.96 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.95

P( $\bar X-1.96 \times {\frac{\sigma}{\sqrt{n} } }$ < $\mu$ < $\bar X+1.96 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.95

95% confidence interval for $\mu$ = [ $\bar X-1.96 \times {\frac{\sigma}{\sqrt{n} } }$ , $\bar X+1.96 \times {\frac{\sigma}{\sqrt{n} } }$ ]

= [ $5.15-1.96 \times {\frac{1.68}{\sqrt{4400} } }$ , $5.15+1.96 \times {\frac{1.68}{\sqrt{4400} } }$ ]

= [5.10 , 5.20]

Therefore, 95% confidence interval for the mean time required to earn a bachelor’s degree by all college students is [5.10 years , 5.20 years].

8 0

3 years ago

A circle has a diameter of 12 feet. What is the circumference of the circle?

Lady bird [3.3K]

Answer:

B). 37.68 feet.

Step-by-step explanation:

Circumference = diameter * π

= 12 * π

= 37.68 feet.

5 0

3 years ago

A right triangle has coordinates A(6, 0), B(0, 0), and C(0, 8). What is the perimeter of the triangle?

dimulka [17.4K]

Answer:

Step-by-step explanation:

From the given coordinates

A(6, 0), B(0, 0) then AB = 6 - 0 = 6

B(0, 0), C(0, 8) then BC = 8 - 0 = 8

To calculate AC use Pythagoras' theorem on the right triangle formed

AC² = AB² + BC² = 6² + 8² = 36 + 64 = 100

Take the square root of both sides, hence

AC = $\sqrt{100}$ = 10

Perimeter = AB + BC + AC = 6 + 8 + 10 = 24 → C

5 0

3 years ago

Urgent, please i will give brainliest

Ne4ueva [31]

Answer:

1. $\frac{\sqrt{13} }{3}$

2. 3.2362

3. $\frac{60}{11}$

Step-by-step explanation:

Cot is the trigonometric ratio defined by "adjacent" over "opposite". So, adjacent = 2 and opposite = 3.

By pythagorean theorem, we have the "hypotenuse" as $\sqrt{2^2+3^2}=\sqrt{13}$

Csc is defined as the trig ratio "hypotenuse" over "opposite". We know the sides, so Csc $\theta$ = $\frac{\sqrt{13} }{3}$

First answer choice is right.

By definition, Csc $\theta$ is the inverse of Sine $\theta$ . If given the value of sin theta, to find value of csc theta, we take the reciprocal of it. Hence:

$Csc\theta=\frac{1}{0.3090}\\=3.2362$

Third answer choice is right.

By definition tan and cot are inverse of each other. So the value of tan is the reciprocal of the value of cot. We can simply "flip" the value of tan theta to get the value of cot theta. Hence:

$Cot\theta=\frac{60}{11}$

Third answer is right.

3 0

3 years ago

Read 2 more answers