What is the sum of -1/2 and 8/6 please help

sweet [91]

F(x)=-5t^2+20t+60
Divide everything by -5
f(x)=t^2-4t-12
(t-6)(t+2)
Set it up to zero
t-6=0. t+2=0
t=6. t=-2
Since you can’t have negative seconds, the answer is 6 seconds

3 0

3 years ago

Read 2 more answers

When the author visited Dublin, Ireland (home of Guinness Brewery employee William Gosset, who first developed the t distributio

disa [49]

Answer:

The Decision Rule

Fail to reject the null hypothesis

The conclusion

There is no sufficient evidence to support the claim that the mean age of the cars is greater than that of taxi

Step-by-step explanation:

From the question we are told that

The data is

Car Ages 4 0 8 11 14 3 4 4 3 5 8 3 3 7 4 6 6 1 8 2 15 11 4 1 6 1 8

Taxi Ages 8 8 0 3 8 4 3 3 6 11 7 7 6 9 5 10 8 4 3 4

The level of significance $\alpha = 0.05$

Generally the null hypothesis is $H_o : \mu_1 - \mu_2 = 0$

the alternative hypothesis is $H_a : \mu_1 - \mu_2 > 0$

Generally the sample mean for the age of cars is mathematically represented as

$\= x_1 = \frac{\sum x_i }{n}$

=> $\= x_1 = \frac{4+ 0+ 8 +11 + \cdots + 8
}{27}$

=> $\= x_1 = 5.56$

Generally the standard deviation of age of cars

$\sigma _1 = \sqrt{\frac{\sum (x_i - \= x)^2}{n_1} }$

=> $\sigma _1 = \sqrt{\frac{(4 - 5.56)^2 + (0 - 5.56)^2+ (8 - 5.56)^2 + \cdots + 8}{ 27} }$

=> $\sigma _1 = 3.88$

Generally the sample mean for the age of taxi is mathematically represented as

$\= x_2 = \frac{\sum x_i }{n}$

=> $\= x_2 = \frac{8 +8 +0 + \cdots + 4
}{20}$

=> $\= x_2 = 5.85$

Generally the standard deviation of age of taxi

$\sigma _2 = \sqrt{\frac{\sum (x_i - \= x)^2}{n_1} }$

=> $\sigma _2 = \sqrt{\frac{(8 - 5.85)^2 + (8 - 5.85)^2+ (0 - 5.85)^2 + \cdots + 8}{ 20} }$

=> $\sigma _2 = 2.83$

Generally the test statistics is mathematically represented as

$t = \frac{(\= x_ 1 - \= x_2 ) - 0}{\sqrt{\frac{\sigma^2_1}{n_1} + \frac{\sigma^2_2}{n_2} } }$

=> $t = \frac{(5.56 - 5.85 ) - 0}{\sqrt{\frac{(3.88)^2}{27} + \frac{(2.83)}{20} }}$

=> $t = -0.30$

Generally the degree of freedom is mathematically represented as

$df = n_1 + n_2 -2$

$df = 27 + 20 -2$

$df = 45$

From the t distribution table the $P(t > t )$ at the obtained degree of freedom = 45 is

$P(t > -0.30 ) = 0.61722067$

So the p-value is

$p-value = P(t > T) = 0.61722067$

From the obtained values we see that the p-value > $\alpha$ hence we fail to reject the null hypothesis

Hence the there is no sufficient evidence to support the claim that the mean age of the cars is greater than that of taxi

5 0

3 years ago

I need Help plsssss!!!!!

laiz [17]

Answer:

2x - 3

x - 9

Step-by-step explanation:

The root of a problem is the x value that makes the equation equal to zero.

If the factored form of the equation is (2x-3)(x-9) that means if either 2x - 3 or x - 9 is equal to zero, the entire equation will equal zero, because zero times any number is equal to zero.

Therefore you must solve for (2x-3)=0 and (x-9)=0

4 0

3 years ago

Can y’all help me pls

krok68 [10]

Answer:

2. The change in expected height for every one additional centimeter of femur length.

Step-by-step explanation:

1. The expected height for someone with a femur length of 65 centimeters.

Doesn't make sense, that would be height value when centimeters = 65.

2. The change in expected height for every one additional centimeter of femur length.

Makes sense, for every increase in one additional centimeter, we can expect the height to be proportional to the slope.

3. The femur length for someone with an expected height of 2.5 centimeters.

Doesn't make sense, the linear relationship relies on the femur length to get the height.

4. The change in expected femur length for every one additional centimeter of height.

Doesn't make sense, again, the linear relationship relies on the femur length.

6 0

2 years ago

<img src="https://tex.z-dn.net/?f=4x%5E%7B2%7D%20%2B4x%2B1%3D0" id="TexFormula1" title="4x^{2} +4x+1=0" alt="4x^{2} +4x+1=0" ali

Arturiano [62]

$D=b^2-4ac\\D=4^2-4(4)(1)\\D=16-16\\D=0$

Meaning there's only 1 real root, complete the square and you get the answer.

$(x+y)^2=x^2+2xy+y^2$

We're going to use this formula, so if x² = 4x² then x = 2x

and if y² = 1 then y = 1

Straight to formula

$(2x+1)^2=0\\x=-\frac{1}{2}$

Because (2x+1)² is basically (2x+1)(2x+1), we get the same value of x.

So the answer is x = -1/2

(When D>0, there are 2 real roots.)

(When D=0, there are only 1 real root.)

(When D<0, there are no real roots, but 2 complex roots.)

8 0

3 years ago