What is the perimeter of ΔYXZ? 3.5 in. 5.3 in. 6.4 in. 7.8 in.

. A conductor with a diameter of 100 mils has an area of

Zielflug [23.3K]

In order to answer the question, you need to know the area of a circle.
Area = pi * r^2
Area = 3.14 * (100/2) ^ 2
Area = 3.14 * 50^2
Area = 7850 mils^2 = 0.00785 in^2

7 0

2 years ago

Two major automobile manufacturers have produced compact cars with engines of the same size. We are interested in determining wh

snow_tiger [21]

Answer:

Step-by-step explanation:

Corresponding fuel efficiencies of manufacturer A's car and manufacturer B's car form matched pairs.

The data for the test are the differences between the efficiencies of manufacturer A's car and manufacturer B's car

μd = fuel efficiency of manufacturer A's car minus the fuel efficiency of manufacturer B's car.

A B diff

32 28 4

27 22 5

26 27 - 1

26 24 2

25 24 1

29 25 4

31 28 3

25 27 - 2

Sample mean, xd

= (4 + 5 - 1 + 2 + 1 + 4 + 3 - 2)/8 = 2

xd = 2

Standard deviation = √(summation(x - mean)²/n

n = 8

Summation(x - mean)² = (4 - 2)^2 + (5 - 2)^2 + (- 1 - 2)^2 + (2 - 2)^2 + (1 - 2)^2 + (4 - 2)^2 + (3 - 2)^2 + (- 2 - 2)^2 = 44

Standard deviation = √(44/8

sd = 2.35

For the null hypothesis

H0: μd = 0

For the alternative hypothesis

H1: μd ≠ 0

This is a two tailed test and the distribution is a students t. Therefore, degree of freedom, df = n - 1 = 8 - 1 = 7

2) The formula for determining the test statistic is

t = (xd - μd)/(sd/√n)

t = (2 - 0)/(2.35/√8)

t = 2.41

We would determine the probability value by using the t test calculator.

p = 0.047

Since alpha, 0.1 > the p value 0.047, then we would reject the null hypothesis. Therefore, at 1% significance level, we can conclude that there is a significant difference in the mean MPG (miles per gallon) when testing for the fuel efficiency of these two brands of automobiles.

6 0

2 years ago

A research organization wanted to estimate the average number of hours a college student sleeps per night during the school year

Alekssandra [29.7K]

Answer:

Step-by-step explanation:

Given given that

Lower confidence interval = 7.1

Upper confidence interval = 7.5

As such, We are 95% confident that it's somewhere between 7.1 and 7.5 hours per night

Average value = LCI + UCI /2 = 7.1 + 7.5 / 2

= 7.3hours per night, so we are 95% confident that it's somewhere between 7.1 and 7.5 hours per night which is eventually 7.3hrs per night.

4 0

2 years ago

A random draw is being designed for 210 participants. A single winner is to be chosen, and all the participants must have an equ

Over [174]

Answer: The correct number of balls is (b) 4.

Step-by-step explanation: Given that a single winner is to be chosen in a random draw designed for 210 participants. Also, there is an equal probability of winning for each participant.

We are using 10 balls, numbered through 0 to 9. We are to find the number of balls which needs to be picked up, regardless of order, so that each of the 210 participants can be assigned a unique set of numbers.

Let 'r' represents the number of balls to be picked up.

Since we are choosing from 10 balls, so we must have

$^{10}C_r=210.$

The value of 'r' can be any one of 0, 1, 2, . . , 10.

Now,

if r = 1, then

$^{10}C_1=\dfrac{10!}{1!(10-1)!}=\dfrac{10!}{1!9!}=\dfrac{10\times 9!}{1\times 9!}=10$

If r = 2, then

$^{10}C_2=\dfrac{10!}{2!(10-2)!}=\dfrac{10!}{2!8!}=\dfrac{10\times 9\times 8!}{2\times 1\times 8!}=45$

If r = 3, then

$^{10}C_3=\dfrac{10!}{3!(10-3)!}=\dfrac{10!}{3!7!}=\dfrac{10\times 9\times 8\times 7!}{3\times 2\times 1\times 7!}=120$

If r = 4, then

$^{10}C_4=\dfrac{10!}{4!(10-4)!}=\dfrac{10!}{4!6!}=\dfrac{10\times 9\times 8\times\times 7\times 6!}{4\times 3\times 2\times 1\times 6!}=210.$

Therefore, we need to pick 4 balls so that each participant can be assigned a unique set of numbers.

Thus, (b) is the correct option.

4 0

2 years ago

Read 2 more answers

Celia bought a bag of 121212 goldfish for \$3$3dollar sign, 3.

muminat

Celia bought a bag of 12 goldfish for $3, Cost of 1 goldfish is $0.25 .

Step-by-step explanation:

The goldfish is a freshwater fish in the family Cyprinidae of order Cypriniformes. It is one of the most commonly kept aquarium fish. A relatively small member of the carp family, the goldfish is native to East Asia.

Here we have , Celia bought a bag of 12 goldfish for $3 . We need to find the cost of 1 goldfish . Let's find out:

Celia have a bag of 12 goldfish which cost her $3 . So , cost of 1 goldfish is equivalent to

⇒ $(1)\frac{12}{3}$

⇒ $(1)\frac{3(4)}{3}$

⇒ $\frac{1}{4}$

⇒ $0.25$

Therefore, Celia bought a bag of 12 goldfish for $3 , Cost of 1 goldfish is $0.25 .

5 0

2 years ago