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3 years ago

Find the value of a? A) 3 B) 4 C) 6 D) 9

Mathematics

1 answer:

tigry1 [53]3 years ago

4 0

Answer:

Step-by-step explanation:

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- Find the difference of 8x and twice the sum<br>of x and 7. Write your answer in simplest<br>form.

9966 [12]

Answer:

7*2=14 8x=8*8=64*2

Step-by-step explanation:

Thats how you basically do it now try it!

5 0

3 years ago

A random sample of 10 parking meters in a beach community showed the following incomes for a day. Assume the incomes are normall

Vlad1618 [11]

Answer: (2.54,6.86)

Step-by-step explanation:

Given : A random sample of 10 parking meters in a beach community showed the following incomes for a day.

We assume the incomes are normally distributed.

Mean income : $\mu=\dfrac{\sum^{10}_{i=1}x_i}{n}=\dfrac{47}{10}=4.7$

Standard deviation : $\sigma=\sqrt{\dfrac{\sum^{10}_{i=1}{(x_i-\mu)^2}}{n}}$

$=\sqrt{\dfrac{(1.1)^2+(0.2)^2+(1.9)^2+(1.6)^2+(2.1)^2+(0.5)^2+(2.05)^2+(0.45)^2+(3.3)^2+(1.7)^2}{10}}$

$=\dfrac{30.265}{10}=3.0265$

The confidence interval for the population mean (for sample size <30) is given by :-

$\mu\ \pm t_{n-1, \alpha/2}\times\dfrac{\sigma}{\sqrt{n}}$

Given significance level : $\alpha=1-0.95=0.05$

Critical value : $t_{n-1,\alpha/2}=t_{9,0.025}=2.262$

We assume that the population is normally distributed.

Now, the 95% confidence interval for the true mean will be :-

$4.7\ \pm\ 2.262\times\dfrac{3.0265}{\sqrt{10}} \\\\\approx4.7\pm2.16=(4.7-2.16\ ,\ 4.7+2.16)=(2.54,\ 6.86)$

Hence, 95% confidence interval for the true mean= (2.54,6.86)

7 0

3 years ago

You eam (4x + 12) points after completing x levels of a video game and

EastWind [94]

Answer: (4x+12) - (2x-5)

Step-by-step explanation: The (4x+12) is positive and the (2x-5) is negative.

5 0

3 years ago

F(x)=2x+5 find f(-6)

ser-zykov [4K]

Answer:

Step-by-step explanation:

f(x) = 2x + 5

f(-6)= 2(-6) + 5 = -12 + 5 = -7

4 0

3 years ago

12. Four less than the quotient of a number and 3 is -10.

Scilla [17]

Answer:

n/3 - 4 = 10

Step-by-step explanation:

hope this helps

5 0

3 years ago