Explain why 4 times 3/5= 4times 3= 12/5

A manager records the repair cost for 4 randomly selected TVs. A sample mean of $88.46 and standard deviation of $17.20 are subs

WINSTONCH [101]

Answer:

a) The critical value is $z = 2.575$ .

b) The 99% confidence interval for the mean repair cost for the TVs is ($66.31, $110.61).

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.99}{2} = 0.005$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ . This is our critical value

So it is z with a pvalue of $1-0.005 = 0.995$ , so $z = 2.575$

a. Find the critical value that should be used in constructing the confidence interval.

The critical value is $z = 2.575$ .

b. Construct the 99% confidence interval. Round your answer to two decimal places.

Now, find M as such

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample. So, in this problem

$M = 2.575*\frac{17.20}{\sqrt{4}} = 22.15$

The lower end of the interval is the mean subtracted by M. So it is 88.46 - 22.15 = $66.31

The upper end of the interval is the mean added to M. So it is 88.46 - 22.15 = $110.61

The 99% confidence interval for the mean repair cost for the TVs is ($66.31, $110.61).

5 0

3 years ago

Complete the equivalent fraction equation below. Blank over two equals two over blank equals blank over eight

podryga [215]

1 over 2 equals 2 over 4 equals 4 over 8.
Hope this helps! :)

5 0

4 years ago

A line has a slope of -3 and includes the point (-5,4) and (-7,q). What is the value of q

serious [3.7K]

Answer:

q = 10

Step-by-step explanation:

$\text{slope} =-3=\frac{q-4}{-7-(-5)} =\frac{q-4}{-2} \\\Longrightarrow -3=\frac{q-4}{-2} \\\Longrightarrow \left( -3\right) \times \left( -2\right) =q-4\\\Longrightarrow 6=q-4\\\Longrightarrow q=6+4\\\Longrightarrow q=10$

8 0

2 years ago

PLEASE HELP!!! WILL GIVE BRAINLEST AWARD FOR MOST DESCRIPTIVE

Rashid [163]

The law of cosines states that:

c^2=a^2+b^2-2abcosC

You already have all the values for the variables with the exception of x so:

x^2=25+100-100cos60

x=√(125-100cos60)

x=√75

x≈8.66 to nearest one-hundredth...

3 0

3 years ago

Last year 40 people adopted a manatee through fia's foundation. This year 30% more people adopted a manatee. How many people ado

Natali [406]

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Answer:

Your answer would be 52 people.

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Step-by-step explanation:

To solve a problem like this, we would want to find out the TOTAL amount of people after figuring out how much increased.

In the question, it is saying that there was a 30% increase from the 40 people that adopted a manatee last year.

There are two ways to solve this:

First way to solve this, we would need to figure out how much is 30% of 40.

To do that, we would multiply 40 by 0.30

40 × 0.30 = 12

Now we found how much 30% of 40 is. What we have to do now is add 40 and 12 to get the total amount of people that adopted a manatee this year.

40 + 12 = 52

Second way to solve it:

This is probably the more faster way to solve the question like this. We know that the increase was 30%, and that last years number was 40. So we would multiply 40 by 1.3

40 × 1.3 = 52

The second way is probably more quicker than the first, but it's your choice on which way you want to use. They both will give you the same answer at the end.

Your FINAL answer would be 52 people.

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4 0

4 years ago