Ask question

Ask question

All categories

2 years ago

5

The time that a skier takes on a downhill course has a normal distribution with a mean of12.3 minutes and standard deviation of

0.4 minutes.
The probability that on a random run the skier takes between 12.1 and 12.5 minutes is ____.

a) 0.1915 b) 0.383 c) 0.3085 d) 0.617

1 answer:

Tems11 [23]2 years ago

8 0

Answer:

Option b

Step-by-step explanation:

Given that the time that a skier takes on a downhill course has a normal distribution with a mean of 12.3 minutes and standard deviation of 0.4 minutes.

If X is the time that the skier takes then

X is N(12.3,0.4)

To convert this to Z score we can use the following

$z=\frac{x-12.3}{0.4}$

The probability that on a random run the skier takes between 12.1 and 12.5 minutes

= $P(12.1$

=0.383

Option b is right.

You might be interested in

A business school professor uses multiple choice tests. Each question on his exams has five possible answers which are assumed t

avanturin [10]

Answer:

a. The null hypothesis for this test is that the observed distribution is the same as uniform distribution

b. The degrees of freedom do you have for this test is 4

c. The calculated value of the test statistic is 9.250

Step-by-step explanation:

a. According to the given data we can conclude that the null hypothesis for this test is that the observed distribution is the same as uniform distribution.

b. In order to calculate the degrees of freedom do you have for this test we would have to make the following calculation:

degrees of freedom=k-1

degrees of freedom=5-1

degrees of freedom=4

c. In order to calculate the value of the test statistic first we have to calculate the frecuency expected as follows:

expected frecuency=total observed frecuency/total number of category

expected frecuency=1,000/5

expected frecuency=200

Hence, to calculate the value of the test statistic we have to calculate the following formula:

x∧2=∑(fo-fe)∧2/fe

=(185-200)∧2/200+(230-200)∧2/200+(215-200)∧2/200+(180-200)∧2+(190-200)∧2

=9.250

The calculated value of the test statistic is 9.250

7 0

2 years ago

The table shows the number of hours of sleep all members of a theater group got the night before their musical.

Neko [114]

The Sample Mean of hours slept of the ten men asked is 8.4 hours.

The population Mean of hours slept of all the members of the theater group is 8.3 hours.

8 0

2 years ago

Read 2 more answers

Alice is shopping for cheese. She notices that the cheddar and brie have the same volume, even though their shapes are different

shutvik [7]

The correct answer is B: 4 cm

6 0

2 years ago

Read 2 more answers

6 questions = 30 points someone please help me

eduard

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

<u>Answer is A) Store 1 has more sales revenue</u>

Answer for Question 4

$\frac{5}{12}=0.4167\\\frac{5}{11}=0.4545$

You can straight away discard answer D because it is less than both 5/12 and 5/11.

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

$\frac{11}{23} =0.4782$ , therefor this is not in between those two numbers.

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 $y=mx+c$

here m is the gradient and c is the intercept.

Find the intercept(c) by finding the y value when x value is 0, here it is +1.

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

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

Therefor the equation of the graph is,

$y=2x+1$

<u>Answer is C</u>

Answer for question 7

$\frac{7}{8} =0.875$

$\frac{6}{9} =0.67$

We can discard answer A because the value is close to 0.5

We can discard answer B because 3/17 is a very small value (0.17)

$\frac{53}{72} =0.73$ , This falls between the above 2 numbers.

<u>Therefor answer is C</u>

5 0

2 years ago

You are a mechanic who is measuring the valve clearance on a motorcycle engine. The current clearance for one of the valves is 0

iren2701 [21]

Answer:

.

Step-by-step explanation:

5 0

1 year ago