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3 years ago

How do you solve -(-7)

Mathematics

2 answers:

tresset_1 [31]3 years ago

7 0

The answer to -(-7) is 7

Hoochie [10]3 years ago

7 0

Answer:

it 7

Step-by-step explanation:

Multiply negative one by negative seven which is positive seven

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Jacob Lee is a frequent traveler between Los Angeles and San Diego. For the past month, he wrote down the flight times in minute

valkas [14]

Solution :

We know that

$H_0: \mu_1 = \mu_2=\mu_3$

$H_1 :$ At least one mean is different form the others (claim)

We need to find the critical values.

We know k = 3 , N = 35, α = 0.05

d.f.N = k - 1

= 3 - 1 = 2

d.f.D = N - k

= 35 - 3 = 32

SO the critical value is 3.295

The mean and the variance of each sample :

Goust Jet red Cloudtran

$\overline X_1 =50.5$ $\overline X_2 =50.07143$ $\overline X_3 =55.71429$

$s_1^2=19.96154$ $s_2^2=14.68681$ $s_3^2=36.57143$

The grand mean or the overall mean is(GM) :

$\overline X_{GM}=\frac{\sum \overline X}{N}$

$=\frac{51+51+...+49+49}{35}$

= 52.1714

The variance between the groups

$s_B^2=\frac{\sum n_i\left( \overline X_i - \overline X_{GM}\right)^2}{k-1}$

$=\frac{\left[14(50.5-52.1714)^2+14(52.07143-52.1714)^2+7(55.71426-52.1714)^2\right]}{3-1}$

$=\frac{127.1143}{2}$

= 63.55714

The Variance within the groups

$s_W^2=\frac{\sum(n_i-1)s_i^2}{\sum(n_i-1)}$

$=\frac{(14-1)19.96154+(14-1)14.68681+(7-1)36.57143}{(14-1)+(14-1)+(7-1)}$

$=\frac{669.8571}{32}$

= 20.93304

The F-test statistics value is :

$F=\frac{s_B^2}{s_W^2}$

$=\frac{63.55714}{20.93304}$

= 3.036212

Now since the 3.036 < 3.295, we do not reject the null hypothesis.

So there is no sufficient evidence to support the claim that there is a difference among the means.

The ANOVA table is :

Source Sum of squares d.f Mean square F

Between 127.1143 2 63.55714 3.036212

Within 669.8571 32 20.93304

Total 796.9714 34

3 0

3 years ago

What is the volume of the prism?

mezya [45]

Answer:

40 $\frac{5}{8}$ $cm^{3}$

Step-by-step explanation:

The figure is a rectangular prism, so the formula would be Volume = length x width x height.

length = 6 $\frac{1}{2}$ cm

width = 2 $\frac{1}{2}$ cm

height = 2 $\frac{1}{2}$ cm

If you plug everything you have in the problem into the volume equation, you would get : Volume = 6 $\frac{1}{2}$ cm x 2 $\frac{1}{2}$ cm x 2 $\frac{1}{2}$ cm.

Without a calculator, I would first turn the mixed numbers into improper fractions.

6 $\frac{1}{2}$ = $\frac{13}{2}$

2 $\frac{1}{2}$ = $\frac{5}{2}$

Volume = $\frac{13}{2}$ x $\frac{5}{2}$ x $\frac{5}{2}$

When you multiply everything together you should get $\frac{325}{8}$ .

As a mixed number, that would be 40 $\frac{5}{8}$ $cm^{3}$ .

7 0

3 years ago

The following data values represent a population. What is the variance of the

Ann [662]

Answer:

B 14 is the correct answer

8 0

2 years ago

Max spends three times as long on his math homework than he does on his science homework. If he spent total of 64 minutes on mat

den301095 [7]

Let X = science homework.

Then math homework would be 3x ( three times as long).

Now you have math plus science = 64 minutes:

x + 3x = 64

Combine like terms:

4x = 64

Divide both sides by 4:

x = 64 / 4

x = 16

He spent 16 minutes on science and 48 minutes on math.

6 0

3 years ago

What is a six sided shape called?

adell [148]

Answer:

hexagon

Step-by-step explanation:

7 0

2 years ago

How do you solve -(-7) ​

How do you solve -(-7)