A set of solar batteries is used in a research satellite. The satellite can run on only one battery, but it runs best if more than one battery is used. The variance σ2 of lifetimes of these batteries affects the useful lifetime of the satellite before it goes dead. If the variance is too small, all the batteries will tend to die at once. Why? If the variance is too large, the batteries are simply not dependable. Why? Engineers have determined that a variance of σ2 = 23 months (squared) is most desirable for these batteries. A random sample of 30 batteries gave a sample variance of 16.3 months (squared). Using a 0.05 level of significance, test the claim that σ2 = 23 against the claim that σ2 is different from 23.

Answer:

y-intercept is (0, -21)

Step-by-step explanation:

For y-intercept, x = 0:

[tex]{ \sf{y + 11 = - 2(0 + 5)}} \\ { \sf{y + 11 = - 10}} \\ { \sf{y = - 21}}[/tex]

Answer:

1. 16%

2. The middle 95% of newborn babies weigh between 6.2 and 9 pounds.

3. 2.5%

4. Approximately 50% of newborn babies weigh more than 7.6 pounds.

5. 83.85%

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

Approximately 68% of the measures are within 1 standard deviation of the mean.

Approximately 95% of the measures are within 2 standard deviations of the mean.

Approximately 99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean of 7.6 pounds, standard deviation of 0.7 pounds

1. What percent of newborn babies weigh more than 8.3 pounds?

7.6 + 0.7 = 8.3.

So more than 1 standard deviation above the mean.

The normal distribution is symmetric, which means that 50% of the measures are below the mean and 50% are above.

Of those above the mean, 100 - 68 = 32% are more than one standard deviation above the mean. So

[tex]0.32*0.5 = 0.16[/tex]

16% of newborn babies weigh more than 8.3 pounds.

2. The middle 95% of newborn babies weigh between and pounds.

Within 2 standard deviations of the mean, so:

7.6 - 2*0.7 = 6.2 pounds

7.6 + 2*0.7 = 9 pounds.

The middle 95% of newborn babies weigh between 6.2 and 9 pounds.

3. What percent of newborn babies weigh less than 6.2 pounds?

More than 2 standard deviations below the mean, which is 5% of the 50% below the mean, so:

[tex]p = 0.05*0.5 = 0.025[/tex]

2.5% of newborn babies weigh less than 6.2 pounds.

4. Approximately 50% of newborn babies weigh more than pounds.

Due to the symmetry of the normal distribution, the mean, so 7.6 pounds.

Approximately 50% of newborn babies weigh more than 7.6 pounds.

5. What percent of newborn babies weigh between 6.9 and 9.7 pounds?

6.9 = 7.6 - 0.7

9.7 = 7.6 + 3*0.7

Within 1 standard deviation below the mean(68% of the 50% below) and 3 standard deviations above the mean(99.7% of the 50% above). So

[tex]p = 0.68*0.5 + 0.997*0.5 = 0.8385[/tex]

83.85% of newborn babies weigh between 6.9 and 9.7 pounds.

Answer:

Step-by-step explanation:

Answer: Number 1 is 150

Step-by-step explanation: If you put 72 / 48% in your calculator, you will get your answer.

Answer:

y  ≥ 5x+ (-3)

Step-by-step explanation:

greater than or equal to ≥

The sum means add

y  ≥ 5x+ (-3)

Answer:

Option D, y ≥ 5x + (-3)

Step-by-step explanation:

Step 1:  Make an expression

The value of y is greater than or equal to the sum of five times the value of x  and negative three.

The value of y is greater than or equal to ← y ≥

The sum of five times the value of x  and negative three ← 5x + (-3)

y ≥ 5x + (-3)

Answer:  Option D, y ≥ 5x + (-3)

Answer:

33.00 355.2

5.0m x 6.7m 33.50 360.6

5.0m x 6.8m 34.00 366.0

5.0m x 6.9m 34.50 371.4

5.1m x 6.0m 30.60 329.4

5.1m x 6.1m 31.11 334.9

5.1m x 6.2m 31.62 340.4

5.1m x 6.3m 32.13 345.8

5.1m x 6.4m 32.64 351.3

5.1m x 6.5m 33.15 356.8

5.1m x 6.6m 33.66 362.3

5.1m x 6.7m 34.17 367.8

5.1m x 6.8m 34.68 373.3

5.1m x 6.9m 35.19 378.8

work and answers below

Answer:

[tex]\text{Part A.}\\(-\frac{1}{8},0),\\(\frac{3}{2},0)\\\\\text{Part B.}\\(\frac{11}{16},\frac{169}{16})\\\\\text{Part C.}[/tex]

Draw a parabola concave down with vertex at [tex](\frac{11}{16},\frac{169}{16})[/tex]. Since the leading coefficient of the equation is -16, the parabola should appear thinner than its parent function [tex]y=x^2[/tex]. Ensure that the parabola passes through the points [tex](\(-\frac{1}{8},0)[/tex] and [tex](\frac{3}{2},0)[/tex].

Step-by-step explanation:

Part A:

The x-intercepts of a function occur at [tex]y=0[/tex]. Therefore, let [tex]y=0[/tex] and solve for all values of [tex]x[/tex]:

[tex]0=-16x^2+22x+3[/tex]

The quadratic formula states that the real and nonreal solutions to a quadratic in standard form [tex]ax^2+bx+c[/tex] is equal to [tex]x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}[/tex].

In [tex]-16x^2+22x+3[/tex], assign:

Therefore, the solutions to this quadratic are:

[tex]x=\frac{-22\pm\sqrt{22^2-4(-16)(3)}}{2(-16)},\\x=\frac{-22\pm 26}{-32},\\\begin{cases}x=\frac{-22+26}{-32}=\frac{4}{-32}=\boxed{-\frac{1}{8}},\\x=\frac{-22-26}{-32}=\frac{-48}{-32}=\boxed{\frac{3}{2}}\end{cases}[/tex]

The x-intercepts are then [tex]\boxed{(-\frac{1}{8},0)}[/tex] and [tex]\boxed{(\frac{3}{2},0)}[/tex].

Part B:

The a-term is negative and therefore the parabola is concave down. Thus, the vertex will be the maximum of the graph. The x-coordinate of the vertex of a quadratic in standard form [tex]ax^2+bx+c[/tex] is equal to [tex]x=\frac{-b}{2a}[/tex]. Using the same variables we assigned earlier, we get:

[tex]x=\frac{-22}{2(-16)}=\frac{-22}{-32}=\frac{11}{16}[/tex]

Substitute this into the equation of the parabola to get the y-value:

[tex]f(11/16)=-16(11/16)^2+22(11/16)+3,\\f(11/16)=\frac{169}{16}[/tex]

Therefore, the vertex of the parabola is located at [tex]\boxed{(\frac{11}{16},\frac{169}{16})}[/tex]

here's the answer to your question

9514 1404 393

Answer:

  B.  x^2/3^2 + y^2/4^2 = 1

Step-by-step explanation:

The graph looks like a circle, but is not. It is a unit circle scaled by a factor of 3 in the x-direction and a factor of 4 in the y-direction. Thus, its equation is ...

  (x/3)^2 +(y/4)^2 = 1

  x^2/3^2 +y^2/4^2 = 1

Answer:

50?

Step-by-step explanation:

Because its 50 miles per gallon, so gallon time 50 will be the miles? I'm not sure but i think it is

Answer: A=πr²      

A=3.14(1.6inch)²                     r=d/2⇒3.2/2⇒1.6

A=3.14×2.56in²

A=8.0384in²

A≈8.04

now circumference,

C=2πr

C=2×3.14×1.6in

C=10.048in

C≈10.05

Answer:

x=71

Step-by-step explanation:

Since this is an isosceles triangle as indicated by the lines on the sides, the sides lengths are equal.

When the sides are equal, the base angles are equal

x=71

9514 1404 393

Answer:

  162 mi²

Step-by-step explanation:

The area on the map is ...

  18(1 in)²

Then the area on the ground will be ...

  18(3 mi)² = 18·9 mi² = 162 mi²

Answer:

1/6

Step-by-step explanation:

We want to find how long it takes for the bacteria to lose half its size. We can do this by taking one point of the bacteria and finding how long it takes to go to half its size. When t=0, 9300 * (1/64)^t = 9300 * 1 = 9300 as anything to the power of 0 is 1. Therefore, we can solve for t when the end result of the bacteria is 9300/2= 4650, making our equation

4650 = 9300 * (1/64)^t

divide both sides by 9300

1/2 = (1/64)^t

First, we can tell that 2^6 = 64*. Because of this, we can say that (1/2)^6 = 1^6/2^6 = 1/64, so (1/64)^(1/6) = 1/2. We know this because

(1/2)^6 = 64

take the 6th root of both sides

(1/2) = (64)^(1/6)

. This means that t=1/6, so the bacterial culture loses 1/2 of its size every 1/6 seconds

* if this is harder to figure out, e.g. 3 and 729, we can plug (log₃729) into a calculator

Answer:

0.17 seconds

Step-by-step explanation:

i got this correct on Khan   :)

i hope it helps

Answer:

a: 1/12

b: 1/6

c: 1/2

d: 1/2

e: 1/12

f: 1/3

Step-by-step explanation:

Answer:

Step-by-step explanation:

First, I would find the point on the curve. By substituting t=1, I get (x, y). Next, I will try to eliminate the t and make a xy equation. In this case, the t's will cancel out in 'x=t-t-1" which wouldnt make this a curve. To find the equation of the tangent line, find the deretitave of the xy equation, and subsitute x in to find the slope at that point. Next, use point slope form to find the equation at the point.

Answer:

The equation will be "[tex]y=x-3[/tex]".

Step-by-step explanation:

Given:

Points (12, 9) = (x, y)

⇒ [tex]x=9t^2+3[/tex]

then,

 [tex]\frac{dy}{dt}=18t[/tex]

or,

⇒ [tex]y=6t^3+3[/tex]

then,

 [tex]\frac{dy}{dt}=18t^2[/tex]

⇒ [tex]\frac{dy}{dx}=\frac{18t^2}{18t}[/tex]

        [tex]=t[/tex]

By using the point slope form.

The equation of tangent will be:

⇒ [tex]y-9=1(x-12)[/tex]

   [tex]y-9=x-12[/tex]

          [tex]y=x-12+9[/tex]

          [tex]y=x-3[/tex]

Answer:

tk 30

Step-by-step explanation:

5 dozen = 5 * 12 = 60 oranges

12/4 = 3

total cost = 60 * 3 = tk.180

total sell = 50 * 3 = tk 150

total lose = 180 - 150 = tk 30

Answer:

6x+y

Step-by-step explanation:

Answer:

3 =f

Step-by-step explanation:

Since this is a right triangle, we can use trig functions

tan theta = opp/ adj

tan 60 = f/ sqrt(3)

sqrt(3) tan 60 = f

sqrt(3) * sqrt(3) = f

3 =f

Answer:

yeah, teachers kinda suck

9514 1404 393

Answer:

  3 ⇒ 12

Step-by-step explanation:

Apparently "a = b" in this case is used to mean f(a) = b. It appears as though the function is ...

  f(x) = x(x+1)

Then f(3) = 3(3+1) = 3·4 = 12

_____

Additional comment

IMO this is a poor use of the equal sign, which should be reserved for situations where the left side expression has the same value as the right side expression.

Answer:

n+3

Step-by-step explanation:

1/2 × 2(n+3)=n +3

I hope this helps

Answer:

6) 6[tex]\sqrt{2}[/tex]

9) 40

10) [tex]\frac{5\sqrt{2} }{2}[/tex]

11) 13

Step-by-step explanation:

6)A right triangle rule: if 2 legs are equal, the hypotenuse is the length of that leg*[tex]\sqrt{2}[/tex]

9) Pythagorean Theorem

[tex]a^{2} +b^{2} =c^{2}[/tex]

We know the hypotenuse (41) so we substitute that for c and 9 for b now we need to find a

[tex]\sqrt{41^{2}-9^{2} }[/tex] which gives us 40

10) same with #6 but we do the opposite. SInce we have the hypotenuse, we can divide that by [tex]\sqrt{2}[/tex] because we know that if 2 legs are equal, the hypotenuse is multiplied by [tex]\sqrt{2}[/tex]. Multiply the numerator and denominator by [tex]\sqrt{2}[/tex] because we can't have a square root in the denominator.

11) like #9 we have the a and b but we need to find c

a=5 b=12 c=r

so [tex]\sqrt{5^{2}+12^{2} }[/tex] which gives us 13

[tex] {h}^{2} = {p}^{2} + {b}^{2} [/tex]

[tex] {c}^{2} = {6}^{2} + {6}^{2} \\ {c}^{2} = 36 + 36 \\ c = \sqrt{2( {6}^{2} )} \\ c = \sqrt{2}{\sqrt{ {6}^{{2}} } } \\ c = 6 \sqrt{2} \: \: \: ans[/tex]

SOLUTION->

[tex] {h}^{2} = {p}^{2} + {b}^{2} [/tex]

[tex] {41}^{2} = {x}^{2} + {9}^{2} \\ 1681 = {x}^{2} + 81 \\ 1681 - 81 = {x}^{2} \\ 1600 = {x}^{2} \\ x = \sqrt{40 \times 40} \\ x = 40 \: \: \: ans[/tex]

GIVEN

[tex]{h}^{2} = {p}^{2} + {b}^{2} [/tex]

[tex] {5}^{2} = {s}^{2} + {s}^{2} \\ 25 = 2 {s}^{2} \\ 12.5 = {s}^{2} \\ \sqrt{12.5} = s \\ 3.5 = s \: \: \: ans[/tex]

[tex] {h}^{2} = {p}^{2} + {b}^{2} [/tex]

[tex] {r}^{2} = {12}^{2} + {5}^{2} \\ {r}^{2} \\ 144 + 25 \\ {r}^{2} = 169 \\ r = \sqrt{13 \times 13} \\ r = 13 \: \: \: \: ans[/tex]

HOPE IT HELPED

[tex] \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \star \: DEVIL005 \: \star[/tex]

9514 1404 393

Answer:

Step-by-step explanation:

The perimeter ratio smaller : larger is the same as the side length ratio.

  18 : 24 = 3 : 4 . . . smaller : larger perimeter ratio

The area ratio is the square of this.

  3^2 : 4^2 = 9 : 16 . . . smaller : larger area ratio

Answer:

0.05, 8%, 15/100, 3/10, 0.7

Step-by-step explanation:

so they are 5%, 8%, 15%, 30%, 70%

Answer:

0.0016 = 0.16% probability that the lot will pass inspection.

Step-by-step explanation:

For each bulb, there are only two possible outcomes. Either it is defective, or it is not. The probability of a bulb being defective is independent of any other bulb, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

Sample of 18 light bulbs

This means that [tex]n = 18[/tex]

30% of the bulbs in the lot are defective.

This means that [tex]p = 0.3[/tex]

What is the probability that the lot will pass inspection?

It will pass inspection if there are no defective bulbs, that is, we have to find P(X = 0). So

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{18,0}.(0.3)^{0}.(0.7)^{18} = 0.0016[/tex]

0.0016 = 0.16% probability that the lot will pass inspection.

answer: 77

Step-by-step explanation:

7×11=77

sorry if I'm wrong

Answer:

fijatebie nl aperguntaa

Step-by-step explanation:

Answer:

x² - √3x / x² - 3

Step-by-step explanation:

To Do :-

Solution :-

We need to rationalize ,

Multiply numerator and denominator by x-√3 :-