Simple true and false question

Can you solve and give me explanation how to solve

Dahasolnce [82]

9514 1404 393

Answer:

3 < x < 6

Step-by-step explanation:

Use the perimeter formula to write an expression for the perimeter. Then put that in an inequality with the given limits. Solve for x.

P = 2(L +W)

P = 2((4x) +(2x +1)) = 2(6x +1) = 12x +2 . . . . . fill in the given values; simplify

The perimeter wants to be between 38 and 74 cm, so we have ...

38 < 12x +2 < 74

36 < 12x < 72 . . . . . subtract 2

3 < x < 6 . . . . . . . . . divide by 6

_____

<em>Additional comment</em>

Solving a compound inequality is very much like solving a single inequality. You need to "undo" what is done to the variable. The rules of equality (ordering) still apply. If you were to multiply or divide by a negative number, the direction (sense) of the inequality symbols would reverse in the same way they do for a single inequality.

Here, our first step was to subtract 2 from all parts of the inequality:

38 -2 < 12x +2 -2 < 74 -2 ⇒ 36 < 12x < 72

The division by 12 worked the same way: all parts are divided by 12.

36/12 < (12x)/12 < 72/12 ⇒ 3 < x < 6

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If it makes you more comfortable, you can treat the perimeter limits as two separate inequalities: 38 < 12x+2 and 12x+2 < 74. Both restrictions apply, so the solution set is the intersection of the solution sets of these separate inequalities.

5 0

3 years ago

The midpoint of AB is M(-2, 1). If the coordinates of A are (-3,-5),

mrs_skeptik [129]

Answer:

B= (-1, 7)

Step-by-step explanation:

Midpoint formula is X1 plus X2, then divided by 2. So, because the midpoint is given you work backwards. So for the x value do (-3 + x) divided by 2 equals -2 and solve for x and you do the same thing for the Y value

8 0

3 years ago

A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It

lapo4ka [179]

Answer:

A. As we are trying to test if the two processes yield different average errors, we are interested in any of the two posibilities: the average error of process A being statistically significant lower or bigger than the average error of Process B. That is why this is a two-tailed test.

B. t=-3.144

C. The critical value for a significance level of 0.05, a two tailed test with 4 degrees of freedom is t=±2.064.

D. P-value = 0.004

E. Reject H0

F. The probability of making a Type I error is equal to the significance level: P(Type I error) = 0.05.

Step-by-step explanation:

This is a hypothesis test for the difference between populations means.

The claim is that the two processes yield different average errors.

As we are trying to test if the two processes yield different average errors, we are interested in any of the two posibilities: the average error of process A being statistically significant lower or bigger than the average error of Process B. That is why this is a two-tailed test.

Then, the null and alternative hypothesis are:

$H_0: \mu_1-\mu_2=0\\\\H_a:\mu_1-\mu_2\neq 0$

being μ1: average error for Process A and μ2: average error fo Process B.

The significance level is 0.05.

The sample 1, of size n1=12 has a mean of 2 and a standard deviation of 1.

The sample 1, of size n1=14 has a mean of 3 and a standard deviation of 0.5.

The difference between sample means is Md=-1.

$M_d=M_1-M_2=2-3=-1$

The estimated standard error of the difference between means is computed using the formula:

$s_{M_d}=\sqrt{\dfrac{\sigma_1^2}{n_1}+\dfrac{\sigma_2^2}{n_2}}=\sqrt{\dfrac{1^2}{12}+\dfrac{0.5^2}{14}}\\\\\\s_{M_d}=\sqrt{0.083+0.018}=\sqrt{0.101}=0.318$