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2 years ago

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* Brittany's teacher tells her that she did well on the Statistics test - her z-score was 1.80 on the test. If the mean score on

the test was a 75 with a standard
deviation of 10, find Brittany's score

1 answer:

Leno4ka [110]2 years ago

8 0

Answer:

93

Step-by-step explanation:

Given that:

Brittany's Zscore = 1.8

Mean score (m) = 75

Standard deviation (s) = 10

Brittany's score (x) =?

Using the Zscore formula :

Zscore = (x - m) / s

1.8 = (x - 75) / 10

18 = x - 75

18 + 75 = x

93 = x

Hence, Brittany's score is 93

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Answer:

1)D

2)D

3)A

4)B

5)Cannot Answer - No data

6)C

7)C

6 Questions answered for 30 points.

Step-by-step explanation:

Answer for the 1st Question,

Area of a cylinder can be calculated by,

Area of the cylindrical part = $2\pi rL$

Area of the parts that cover the open parts of cylinder = $2\pi r^2$

Therefor Total are of the cylinder = $2\pi rL+2\pi r^2$

Area of the total cylinder = $2*3.14*6.8*14.2+2*3.14*6.8^2$

= $896.784$

<u>Therefor best estimate will be D) 923 in^2</u>

Answer for the 2nd Question,

ABC is a triangle.

By Pythagorean theorem it says,

$(AC)^2+(CB)^2=(AB)^2$

The distance from A to C = 6

The distance from C to B = 5

$(AC)^2=6^2=36$

$(CB)^2=5^2=25$

$(AC)^2+(CB)^2=(AB)^2=36+25=61$

Therefor $(AB)^2=61\\(AB)=\sqrt{61}$

<u>Therefor Answer is D) Sqr 61</u>

Answer to Question 3

To find the trend you can draw an imaginary line that fits the scatter plots.(I have attached a image drawing the imaginary lines)

Then the revenue can be calculated by calculating the area covered by the imaginary line drawn or area "under" the curve.

Area of the Store 1 = $\frac{1}{2} *(110+40)*110=8250$

Area of the Store 2= $\frac{1}{2} *110*80=4400$

Therefore Revenue from Store 1 = $8250

Revenue from Store 2 = $4400

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Answer for Question 4

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Also you can discard Answer C because 25/264 is very small (less than 1/10=0.1)

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Then it has to be $\frac{115}{264} =0.4356$

<u>Answer is B)</u>

Answer for question 6

The equation of a straight line is of the form $y=mx+c$

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Gradient (m) of the graph can be found by,

$\frac{y1-y2}{x1-x2} =\frac{7-3}{3-1} =2$

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A local library claims it has 2.73x103 books. If there are 42 people in the building, how many books per capita are there?

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Answer:

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Step-by-step explanation:

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Required

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madreJ [45]

So we are given a system:
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A sample of 1714 cultures from individuals in Florida diagnosed with a strep infection was tested for resistance to the antibiot

Damm [24]

Answer:

a) $p$ represent the real population proportion of people who showed partial or complete resistance to the antibiotic

b) $\hat p=\frac{973}{1714}=0.568$ represent the estimated proportion of people who showed partial or complete resistance to the antibiotic

c) We are confident (95%) that the true proportion of individuals in Florida diagnosed with a strep infection was tested for resistance to the antibiotic penicillin present partial or complete resistance to the antibiotic is between 54.5% to 59.1%.

Step-by-step explanation:

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

Part a

Description in words of the parameter p

$p$ represent the real population proportion of people who showed partial or complete resistance to the antibiotic

$\hat p$ represent the estimated proportion of people who showed partial or complete resistance to the antibiotic

n=1714 is the sample size required

$z_{\alpha/2}$ represent the critical value for the margin of error

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

Part b

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In order to estimate a proportion we use this formula:

$\hat p =\frac{X}{n}$ where X represent the number of people with a characteristic and n the total sample size selected.

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Part c

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$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

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And the 95% confidence interval would be given (0.545;0.591).

We are confident that about 54.5% to 59.1% of individuals in Florida diagnosed with a strep infection was tested for resistance to the antibiotic penicillin present partial or complete resistance to the antibiotic.

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