Someone help plssssss

Scorpion4ik [409]

The correct answer is: [A]: " y = (¾)x + 4 " .
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8 0

3 years ago

A survey collects demographic, socioeconomic, dietary, and health-related information on an annual basis. Here is a sample of 20

garik1379 [7]

Answer:

(a) The point estimate of the population mean HDL cholesterol level is 49.95.

(b) The point estimate of the value that separates the largest 50% of HDL levels from the smallest 50% is 47.5.

(c) The point estimate of the population standard deviation is 16.85.

Step-by-step explanation:

We are given a sample of 20 observations on HDL cholesterol level (mg/dl) obtained from the survey below;

35, 49, 51, 54, 65, 51, 52, 47, 87, 37, 46, 33, 39, 44, 39, 64, 94, 34, 30, 48.

(a) The point estimate of the population mean HDL cholesterol level is given by the sample mean of the above data, i.e;

Sample Mean, $\bar X$ = $\frac{\sum X}{n}$

= $\frac{35+ 49+ 51+ 54 +65 +51+ 52+ 47+ 87+ 37+ 46+ 33+ 39+ 44+ 39+ 64+ 94+ 34+ 30+ 48}{20}$

= $\frac{999}{20}$ = 49.95

So, the point estimate of the population mean HDL cholesterol level is 49.95.

(b) The point estimate of the value that separates the largest 50% of HDL levels from the smallest 50% is given by the Median of the above data.

Firstly, arranging the given data in ascending order we get;

30, 33, 34, 35, 37, 39, 39, 44, 46, 47, 48, 49, 51, 51, 52, 54, 64, 65, 87, 94.

Now, for calculating median we have to first observe that the number of observations (n) in our data is even or odd, i.e;

If n is odd, then the formula for calculating median is given by;

Median = $(\frac{n+1}{2})^{th} \text{ obs.}$

If n is even, then the formula for calculating median is given by;

Median = $\frac{(\frac{n}{2})^{th} \text{ obs.}+(\frac{n}{2}+1)^{th} \text{ obs.} }{2}$

Here, the number of observations is even, i.e. n = 20.

So, Median = $\frac{(\frac{n}{2})^{th} \text{ obs.}+(\frac{n}{2}+1)^{th} \text{ obs.} }{2}$

= $\frac{(\frac{20}{2})^{th} \text{ obs.}+(\frac{20}{2}+1)^{th} \text{ obs.} }{2}$

= $\frac{(10)^{th} \text{ obs.}+(11)^{th} \text{ obs.} }{2}$

= $\frac{47+48 }{2}$

Median = 47.5

Hence, the point estimate of the value that separates the largest 50% of HDL levels from the smallest 50% is 47.5.

(c) The point estimate of the population standard deviation is given by the following formula;

Standard deviation, s = $\sqrt{\frac{\sum(X-\bar X)^{2} }{n-1} }$

= $\sqrt{\frac{ (30-49.95)^{2}+(33-49.95)^{2}+(34-49.95)^{2}+........+(94-49.95)^{2}}{{20-1}} }} }$

= 16.85

8 0

3 years ago

You want to swim across the gulf of mexico, a distance of 1500 km. if you swim at a rate 1 kilometer per hour, how many days wil

nirvana33 [79]

It says 24 hours but the right answer is 25 hours. Tell me what the correct answer is.

3 0

3 years ago

How can 1,6,2,-4 equal 24

krek1111 [17]

Answer: 1,6,2,-4 are equal to 24 because they all equal 24

Step-by-step explanation: 24x1=24, 6x4=24 and so on

7 0

4 years ago

rob can tar a roof in nine hours. one day his friend kayla helped him and it only took 4.74 hrs. how long will it take kayla to

jekas [21]

<span>When 2 people work the formula is: Person1 * Person2 / (Person1 + Person2)
</span>
<span>rob becomes Person1 and Kayla becomes Person 2
9 * K / (9 + K) = 4.74 Hours
9*K = 4.74*9 + K*4.74
9*K = 42.66 + K*4.74 4.26 *K = 42.66 K = 10.014084507 hours (Kayla)
TESTING the answer (9 * 10.014084507) / (9 + 10.014084507) = 4.74 90.126760563 / (19.014084507) = 4.74
4.74 = 4.74
</span>

7 0

3 years ago