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3 years ago

Please help!!!!!!!!!!!!

Mathematics

1 answer:

zzz [600]3 years ago

5 0

480 is the no of people that choose science fiction

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Many smartphones, especially those of the LTE-enabled persuasion, have earned a bad rap for exceptionally bad battery life. Batt

BartSMP [9]

Answer:

Null hypothesis: the variance in hours of usage for talking is not greater than the the variance in hours of usage for internet.

$H_o$ : $\sigma _1 ^2 \leq \sigma _2^2$

Alternative hypothesis: the variance in hours of usage for talking is greater than the the variance in hours of usage for internet.

$H_a : \sigma_1^2 > \sigma_2^2$

$\mathbf{s_ 1 =16.11}$

$\mathbf{s_2 = 7.98}$

Step-by-step explanation:

Let $x_1$ and $x_2$ be the two variables that represents the battery life in hours for talking usage and battery life in hours for internet usage respectively.

The hypothesis can be formulated as:

Null hypothesis: the variance in hours of usage for talking is not greater than the the variance in hours of usage for internet.

$H_o$ : $\sigma _1 ^2 \leq \sigma _2^2$

Alternative hypothesis: the variance in hours of usage for talking is greater than the the variance in hours of usage for internet.

$H_a : \sigma_1^2 > \sigma_2^2$

The standard deviation for the battery usage for talking is :

$\bar x_1 = \dfrac{1}{n_1} \sum x_i \\ \\ \bar x_1 = \dfrac{1}{12}(35.8 +22.4+...+35.5) \\ \\ \bar x_1 = \dfrac{241.2}{12} \\ \\ \bar x_1 =20.1$

The standard deviation Is:

$s_ 1 = \sqrt{\dfrac{1}{n_1-1}\sum (x{_1i}-\bar x_i)^2}$

$s_ 1 = \sqrt{\dfrac{1}{12-1}\sum (35.8- 20.1)^2+ (35.5-20.1)^2}$

$s_ 1 = \sqrt{259.568}$

$\mathbf{s_ 1 =16.11}$

The standard deviation for the battery life usage for the internet is :

$\bar x_2 = \dfrac{1}{n_2} \sum x_{2i}$

$\bar x_2 = \dfrac{1}{10} (24.0+12.5+36.4+...+4.7})$

$\bar x_2 = \dfrac{115}{10}$

$\bar x_2 = 11.5$

Thus; the standard deviation is:

$s_2 = \sqrt{\dfrac{1}{n_2-1}(x_{2i}- \bar x_2)^2}$

$s_2 = \sqrt{\dfrac{1}{10-1}(24-11.5)^2+(4.7-11.5)^2}$

$s_2 = \sqrt{63.60}$

$\mathbf{s_2 = 7.98}$

4 0

3 years ago

How to find out how many number combinations if numbers cannot repeat?

Scrat [10]

It is simple and easy to find out about how many number combinations there are if numbers cant repeat you simply look at which combinations that you are aiming for and find out the different type of ways that you can do to get that same equal numbers that you were hoping to find is simple like 1 + 9 = 10 as same as 5 + 5 =10 its not that hard. HOPE THIS HELPS!!!

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3 years ago

Helllllppp!!!!!!!!!!!!11 marking brainliest!

aalyn [17]

Hello!

Let the unknown number be x.

Subtract 5:

x-5

Double the result: (multiply the result times 2):

2(x-5)

Hope everything is clear.

Let me know if you have any questions!

#KeepLearning

:-)

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2 years ago

-6, -5, -3, -1,... what comes next?

lys-0071 [83]

Answer:

Step-by-step explanation:

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3 years ago

It takes 71 pounds of seed to completely plant a 9 acre field. How many acres can be planted per pound of seed?

Vitek1552 [10]

.12 acres can be planted per pound of seed

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