Given one of the roots of the quadratic equation x2 + kx + 12 = 0 is three times the other root. Find the values of k.

A recent study of 26 city residents showed that the time they had lived at their present address has a mean of 10.3 years with t

svetlana [45]

Answer:

The 95% confidence interval is $9.15< \mu < 11.45$

Step-by-step explanation:

From the question we are told that

The sample size is n = 26

The mean is $\= x = 10.3$

The standard deviation is $s = 3$

From the question we are told the confidence level is 95% , hence the level of significance is

$\alpha = (100 - 95 ) \%$

=> $\alpha = 0.05$

Generally from the normal distribution table the critical value of $\frac{\alpha }{2}$ is

$Z_{\frac{\alpha }{2} } = 1.96$

Generally the margin of error is mathematically represented as

$E = Z_{\frac{\alpha }{2} } * \frac{\sigma }{\sqrt{n} }$

=> $E = 1.96 * \frac{3}{\sqrt{26} }$

=> $E = 1.1532$

Generally 95% confidence interval is mathematically represented as

$\= x -E < \mu < \=x +E$

=> $10.3 -1.1532 < \mu < 10.3 + 1.1532$

=> $9.15< \mu < 11.45$

7 0

3 years ago

HELP! WILL MARK BRAINLIEST!

posledela

Answer: C

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

Rafael reads 3/4 chapters in 4/5 hours

Inessa [10]

I do not know the full question being asked, but if he reads 3/4 chapters in 4/5 hours, he would read 6/4 chapters, or 1 1/2 chapters in 1 3/5 hours.

Please mark Brainliest if helpful!
If this isn’t your question, please provide it fully in the comments of this answer. :))

4 0

3 years ago

Herman Melville had worked at the University Medical Center for 20 years when he became permanently disabled while at work. He c

lidiya [134]

Answer:

Herman Melville's annual disability benefit is $46,114.8

Step-by-step explanation:

Given the data in the question;

Herman Melville is 55 years, worked for 20 years, planned to retire in the next 10 years i.e at the age of 65.

so since he planned to work for the next 10 years;

total duration of work will be; ( 20 + 10) years = 30 years

Average salary per year = $76,908

Total salary in 30 years will be; $76,908 × 30 = $2,307,240

Hospital rate benefits = 2%

So, total annual disability benefit will be;

⇒ 2% of Total salary in 30 years

⇒ 2/100 × $2,307,240

= $46,114.8

Therefore, Herman Melville's annual disability benefit is $46,114.8

4 0

3 years ago

The freezing point of water is 32º F. Tim added potassium and found

HACTEHA [7]

Answer:

The freezing point of the water with the added potassium is 24 degrees Fahrenheit.

Step-by-step explanation:

To find the freezing point of the water with the added potassium, you need to subtract 8 degrees from the initial freezing point of water, This is because you know that after adding potassium to water, the freezing point went down by 8 degrees Fahrenheit. So you need to subtract 8 degrees from the initial freezing point of water (32 degrees Fahrenheit). 32º F - 8º = 24º F. So the freezing point of the water with the added potassium is 24 degrees Fahrenheit.

5 0

2 years ago