Which is the value of this expression when a=-2and b=-3

A weather balloon is at an altitude where the temperature is 3º C. The balloon ascends 900 ft with a decrease in temperature of

igor_vitrenko [27]

Answer:

Answer is -5°C.

Step-by-step explanation:

Initial temperature = 3°C

First decrease in temperature = 5°C

Second decrease in temperature = 3°C

Balloon ascend = 900 ft

Total change in temperature = 3-5-3 = -5

Thus final temperature = -5°C

8 0

3 years ago

What is the value of x? Enter your answer in the box (Please hurry)

GaryK [48]

Answer:

$\large\boxed{x=20}$

Step-by-step explanation:

The whole triangle and small triangle are similar (AA). Therefore the sides are in proportion:

$\dfrac{5x+10+10}{10}=\dfrac{121+11}{11}$

$\drac{5x+20}{10}=\dfrac{132}{11}$ cross multiply

$11(5x+20)=(10)(132)$ use distributive property

$(11)(5x)+(11)(20)=1320$

$55x+220=1320$ subtract 220 from both sides

$55x=1100$ divide both sides by 55

$x=20$

7 0

3 years ago

Variable y varies directly with x2, and y = 96 when x = 4.

lakkis [162]

Direct variation is y = kx, where k is the constant of variation.
But now it says y varies directly with x2 (or 2x), so now the x in the equation is 2x.

The equation is y = k(2x)
Now you find k.
y = 96 when x = 4.
(96) = k(2*4)
96 = k(8)
k = 12

The equation is now y = 12(2x)
To find the value of y when x=2, plug 2 into the equation you made. y = 12(2*2) y = 48
_________________
Now it's with a "quadratic variation," which is the same thing except x is squared.
The equation is y = kx^2

But y varies directly with x2 (same thing as 2x), so now it's y = k(2x)^2.

Now you find k by substituting y and x values that were given.
y = 180 when x = 6
(180) = k(2*6)^2
180 = k(12)^2
180 = k(144)
k = 1.25
k, 1.25, is the constant of variation.

4 0

3 years ago

PLZ HELP! find the value of f(-2) for the function f(x)=4x+10 Show work please

natita [175]

Answer:

f(-2) = +2

Step-by-step explanation:

Let x = -2

So,

f(x) = 4x + 10

Substituting the value of x gives ,

f(-2) = 4 × (-2) + 10 = 10 - 8 = 2

8 0

3 years ago

A group of retired admirals, generals, and other senior military leaders, recently published a report, "Too Fat to Fight". The r

weqwewe [10]

Answer:

$z=\frac{0.694 -0.75}{\sqrt{\frac{0.75(1-0.75)}{180}}}=-1.735$

$p_v =P(z$

If we compare the p value obtained and the significance level given $\alpha=0.05$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% of significance the proportion of americans between 17 to 24 that not qualify for the military is significantly less than 0.75 or 75% .

Step-by-step explanation:

1) Data given and notation

n=180 represent the random sample taken

X=125 represent the number of americans between 17 to 24 that not qualify for the military

$\hat p=\frac{125}{180}=0.694$ estimated proportion of americans between 17 to 24 that not qualify for the military

$p_o=0.75$ is the value that we want to test

$\alpha=0.05$ represent the significance level

Confidence=95% or 0.95

z would represent the statistic (variable of interest)

$p_v$ represent the p value (variable of interest)

2) Concepts and formulas to use

We need to conduct a hypothesis in order to test the claim that less than 75% of Americans between the ages of 17 to 24 do not qualify for the military :

Null hypothesis: $p\geq 0.75$

Alternative hypothesis: $p < 0.75$

When we conduct a proportion test we need to use the z statistic, and the is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

The One-Sample Proportion Test is used to assess whether a population proportion $\hat p$ is significantly different from a hypothesized value $p_o$ .

3) Calculate the statistic

Since we have all the info requires we can replace in formula (1) like this:

$z=\frac{0.694 -0.75}{\sqrt{\frac{0.75(1-0.75)}{180}}}=-1.735$

4) Statistical decision

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.

The significance level provided $\alpha=0.05$ . The next step would be calculate the p value for this test.

Since is a left tailed test the p value would be:

$p_v =P(z$

If we compare the p value obtained and the significance level given $\alpha=0.05$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% of significance the proportion of americans between 17 to 24 that not qualify for the military is significantly less than 0.75 or 75% .

6 0

3 years ago