harold deposits $30 a week into a savings account. hid balance in his savings account grows by a constant rate. true or false

What is the volume, in cubic meters, of a cylinder with a height of 8 meters and a base radius of 9 meters, to the nearest tenth

sammy [17]

Volume of a cylinder: $\pi r^{2} h$

Plug in the numbers.

$\pi 9^{2} 8$ = <span>2035.8
</span>
The cylinder's volume is 2035.8 m³.

5 0

4 years ago

Isaac is allowed to play video games for 5/3 hours a day. He has already played for 4/3 hours today. What fraction of an hour do

iren2701 [21]

1 whole which means 1 hour

8 0

3 years ago

Read 2 more answers

At a local university, a sample of 49 evening students was selected in order to determine whether the average age of the evening

pav-90 [236]

Answer:

$z=\frac{23-21}{\frac{3.5}{\sqrt{49}}}=4$

$p_v =2*P(z>4)=0.0000633$

When we compare the significance level $\alpha=0.1$ we see that $p_v$ so we can reject the null hypothesis at 10% of significance. So the the true mean is difference from 21 at this significance level.

Step-by-step explanation:

Data given and notation

$\bar X=23$ represent the sample mean

$\sigma=3.5$ represent the population standard deviation

$n=49$ sample size

$\mu_o =21$ represent the value that we want to test

$\alpha=0.1$ represent the significance level for the hypothesis test.

z would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the average age of the evening students is significantly different from 21, the system of hypothesis would be:

Null hypothesis: $\mu = 21$

Alternative hypothesis: $\mu \neq 21$

The statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{23-21}{\frac{3.5}{\sqrt{49}}}=4$

P-value

Since is a two sided test the p value would be:

$p_v =2*P(z>4)=0.0000633$

Conclusion

When we compare the significance level $\alpha=0.1$ we see that $p_v$ so we can reject the null hypothesis at 10% of significance. So the the true mean is difference from 21 at this significance level.

8 0

3 years ago

Find x and y on triangle<br>Also the degree is 30 and the other thing is 7sqrt3

nydimaria [60]

Answer:

y =7

x =14

Step-by-step explanation:

Since this is a right triangle we can use trig functions

tan 30 = opp /adj

tan 30 = y/ 7 sqrt(3)

7 sqrt(3) tan 30 = y

7 sqrt(3) * 1/ sqrt(3) =t

7 =y

sin 30 = opp/ hyp

sin 30 = 7/x

x sin 30 =7

x = 7/ sin 30

x = 7 / 1/2

x = 14

6 0

3 years ago

Simplify the expression with using scientific notation (4 times 10 8)2

kifflom [539]

The scientific notation:

$a\cdot10^n\\\\1\leq a < 10;\ n\in\mathbb{Z}$

$(4\cdot10^8)^2=4^2(10^8)^2=16\cdot10^{8\cdot2}=16\cdot10^{16}\\\\=1.6\cdot10\cdot10^{16}=1.6\cdot10^{17}$

Used:

$(a\cdot b)^n=a^n\cdot b^n\\\\(a^n)^m=a^{n\cdot m}\\\\a^n\cdot a=a^{n+1}$

Answer: (4 × 10⁸)² = 1.6 × 10¹⁷

8 0

3 years ago