(-2) with an exponent of four equals what

Arlene had some blackberries. She gave 216 to her teachers. Then she dropped 12. Later, she ate 18. Finally, she gave half of wh

Bingel [31]

Answer:the number of BlackBerry that Arlene had initially was 276

Step-by-step explanation:

Let x represent the number of BlackBerry that Arlene had initially.

She gave 216 to her teachers. This means that she is left with x - 216

Then she dropped 12. This means that she would be left with x - 216 - 12 = x - 228

Later, she ate 18. This means that she would be left with x - 228 - 18 = x - 246

Finally, she gave half of what she had to her friend. This means that the amount that she gave to her friend is (x - 246)/2 and the amount that she has left would be

(x - 246)/2

Now, she has 15. This means that

(x - 246)/2 = 15

x - 246 = 2 × 15 = 30

x = 30 + 246 = 276

7 0

3 years ago

Solve for x.<br><br> 12(x−360)=120 <br><br> Enter your answer in the box.

kenny6666 [7]

12x-4320=120
12x=120+4320
12x=4440
x=370

6 0

3 years ago

Read 2 more answers

5. A scientist believes the concentration of radon gas in the air is greater that the established safe level of 4pci or less. Th

zysi [14]

Complete Question

A scientist believes the concentration of radon gas in the air is greater that the established safe level of 4 pci or less. The scientist tests the composition for 36 days finding an average concentration of 4.4 pci with a sample standard deviation of 1 pci.

a) In testing the scientist's belief, write the appropriate hypotheses:

$H_o:$ Ha:

b) What decision should be made?

Answer:

a

The null hypothesis is $H_o : \mu \le 4 \ pci$

The alternative hypothesis is $H_a : \mu > 4 \ pci$

b

There is sufficient evidence to conclude that the concentration of radon gas in the air is greater that the established safe level of 4pci or less

Step-by-step explanation:

From the question we are told that

The population mean is $\mu = 4 \ pci$

The sample size $n = 36 \ days$

The sample mean is $\= x = 4.4 \ pci$

The standard deviation is $\sigma = 1 \ pci$

The level of significance is $\alpha = 0.05$

The null hypothesis is $H_o : \mu = 4 \ pci$

The alternative hypothesis is $H_a : \mu > 4 \ pci$

Generally the test statistics is mathematically represented as

$t = \frac{ \= x - \mu }{ \frac{ \sigma}{ \sqrt{n} } }$

=> $t = \frac{ 4.4 - 4 }{ \frac{ 1}{ \sqrt{36} } }$

=> $t =2.4$

The p-value is mathematically represented as

$p-value = P(Z > 2.4 )$

From the z-table

$P(Z > 2.4 ) = 0.008$

$p-value =0.008$

So from this obtained value we see that

$p-value < \alpha$ so we reject the null hypothesis

Hence we can conclude that there is sufficient evidence to conclude that the concentration of radon gas in the air is greater that the established safe level of 4pci or less

4 0

4 years ago

The distance of a point ( 0 , -3 ) from the origin is

erma4kov [3.2K]

Answer:

3

Step-by-step explanation:

A(0, -3); O(0,0)

AO=√[(0-0)²+(0+3)²]=√3²=3

7 0

4 years ago

Jim and Holly are making gingerbread men. It takes them both 2 minutes to make 2 gingerbread shapes. At this rate, how many peop

emmainna [20.7K]

Take 400 and divided by 2 which u need 200 more people

7 0

3 years ago