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stealth61 [152]
2 years ago
12

Use the following dot plot to answer the questions.

Mathematics
1 answer:
cupoosta [38]2 years ago
8 0

Answer:

3.4

Decrease ; 3.375

Step-by-step explanation:

Mean = Σfx / Σf

Σfx = (1 * 2) + (2 * 2) + (3 * 3) + (4 * 9) = 51

Σf = 1 + 2 + 3 + 9 = 15

Mean = 51 / 15 = 3.4

If 1 more dot is added to the 3rd column:

Σfx = (1 * 2) + (2 * 2) + (3 * 4) + (4 * 9) = 54

Σf = 1 + 2 + 4 + 9 = 16

Mean = 54 / 16 = 3.375

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What is the answer to 3/5(10x-1/3)-x+6/5
seraphim [82]

Answer:

5x + 1

Step-by-step explanation:

7 0
3 years ago
A random sample of 12 supermarkets from Region 1 had mean sales of 84 with a standard deviation of 6.6. A random sample of 17 su
Sladkaya [172]

Answer:

We conclude that there is no difference in potential mean sales per market in Region 1 and 2.

Step-by-step explanation:

We are given that a random sample of 12 supermarkets from Region 1 had mean sales of 84 with a standard deviation of 6.6.

A random sample of 17 supermarkets from Region 2 had a mean sales of 78.3 with a standard deviation of 8.5.

Let \mu_1 = mean sales per market in Region 1.

\mu_2  = mean sales per market in Region 2.

So, Null Hypothesis, H_0 : \mu_1-\mu_2 = 0      {means that there is no difference in potential mean sales per market in Region 1 and 2}

Alternate Hypothesis, H_A : > \mu_1-\mu_2\neq 0      {means that there is a difference in potential mean sales per market in Region 1 and 2}

The test statistics that will be used here is <u>Two-sample t-test statistics</u> because we don't know about population standard deviations;

                            T.S.  =  \frac{(\bar X_1 -\bar X_2)-(\mu_1-\mu_2)}{s_p \times \sqrt{\frac{1}{n_1}+ {\frac{1}{n_2}}} }   ~  t__n_1_+_n_2_-_2

where, \bar X_1 = sample mean sales in Region 1 = 84

\bar X_2 = sample mean sales in Region 2 = 78.3

s_1  = sample standard deviation of sales in Region 1 = 6.6

s_2  = sample standard deviation of sales in Region 2 = 8.5

n_1 = sample of supermarkets from Region 1 = 12

n_2 = sample of supermarkets from Region 2 = 17

Also, s_p=\sqrt{\frac{(n_1-1)\times s_1^{2}+(n_2-1)\times  s_2^{2}  }{n_1+n_2-2} }  = s_p=\sqrt{\frac{(12-1)\times 6.6^{2}+(17-1)\times  8.5^{2}  }{12+17-2} } = 7.782

So, <u><em>the test statistics</em></u> =  \frac{(84-78.3)-(0)}{7.782 \times \sqrt{\frac{1}{12}+ {\frac{1}{17}}} }  ~   t_2_7

                                   =  1.943  

The value of t-test statistics is 1.943.

 

Now, at a 0.02 level of significance, the t table  gives a critical value of -2.472 and 2.473 at 27 degrees of freedom for the two-tailed test.

Since the value of our test statistics lies within the range of critical values of t, so we have<u><em> insufficient evidence to reject our null hypothesis</em></u> as it will not fall in the rejection region.

Therefore, we conclude that there is no difference in potential mean sales per market in Region 1 and 2.

6 0
3 years ago
Each of the following correctly match an English phrase with a mathematical expression except _____. a number times seven, 7x a
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5:8
3+5=
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6 0
3 years ago
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I need number 1 please and thank you
belka [17]

Answer:

It is the third one because of formula I² + 2I*II + II²

In your case I = 4x and II = 3

4 0
3 years ago
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