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3 years ago

Can someone PLEASE help me with this

Mathematics

2 answers:

shepuryov [24]3 years ago

4 0

The area of triangle ABD is 4.5 cm squared (the last multiple choice option)

Mekhanik [1.2K]3 years ago

3 0

Answer:

4.5 u

Step-by-step explanation:

There are many ways to do it, the most easier is this:

Area=(b*h)/2

Area of ABD = (3*3)/2 = 4.5 u

You might be interested in

If 90 percent of automobiles in Orange County have both headlights working, what is the probability that in a sample of eight au

Marta_Voda [28]

Answer:

$P(X \geq 7) = P(X=7) +P(X=8)$

And we can find the individual probabilities using the probability mass function

$P(X=7)=(8C7)(0.9)^7 (1-0.9)^{8-7}=0.3826$

$P(X=8)=(8C8)(0.9)^8 (1-0.9)^{8-8}=0.4305$

And replacing we got:

$P(X \geq 7) = P(X=7) +P(X=8)=0.3826 +0.4305=0.8131$

Step-by-step explanation:

Previous concepts

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

Solution to the problem

Let X the random variable of interest "number of automobiles with both headligths working", on this case we now that:

$X \sim Binom(n=8, p=0.9)$

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

$nCx=\frac{n!}{(n-x)! x!}$

And for this case we want to find this probability:

$P(X \geq 7) = P(X=7) +P(X=8)$

And we can find the individual probabilities using the probability mass function

$P(X=7)=(8C7)(0.9)^7 (1-0.9)^{8-7}=0.3826$

$P(X=8)=(8C8)(0.9)^8 (1-0.9)^{8-8}=0.4305$

And replacing we got:

$P(X \geq 7) = P(X=7) +P(X=8)=0.3826 +0.4305=0.8131$

7 0

3 years ago

Read 2 more answers

8x-5y=21 simultaneous linear equation<br>2x+9y=-5

olya-2409 [2.1K]

Answer:

$x=2$ and $y=-1$

Step-by-step explanation:

If two equations are given, we can solve one of the equation in terms of single variable and put it in the other equation which will further give the value of x and y.

For the given equations:

$8x-5y=21$ Equation:1

$2x+9y=-5$ Equation:2

Solving equation multiply equation 2 with 4 on both the sides

$8x+36y=-20$ Equation 3

Subtracting Equation:3 from Equation:1

$8x-5y-(8x+36y)=21-(-20)\\8x-5y-8x-36y=21+20\\-41y=41\\y=-1$

Putting value of 'y' in Equation:2 which will give the value of x

$2x+9y=-5\\2x+9(-1)=-5\\2x-9=-5\\2x=4\\x=2$

8 0

3 years ago

The price of an Ice cream cone is $3.25, but it cost $3.51 with tax. What is the sales tax rate?

Mekhanik [1.2K]

Answer:

The sales tax is 8%

8 0

2 years ago

Read 2 more answers

Identify the examples as primary sources or secondary sources.

algol13

Answer:

Primary : letters, artifacts, contracts

Secondary : documentaries, encyclopedias, biographies

Step-by-step explanation:

(I'm not too sure about contracts, so you might want to check yourself for that one)

5 0

3 years ago

A random sample of n observations is selected from a normal population to test the null hypothesis that muμequals=10. Specify th

brilliants [131]

Answer:

Step-by-step explanation:

a) H0: μ = 10

Ha: μ ≠ 10

This is a two tailed test

n = 13

Since α = 0.01, the critical value is determined from the t distribution table. Recall that this is a two tailed test. Therefore, we would find the critical value corresponding to 1 - α/2 and reject the null hypothesis if the absolute value of the test statistic is greater than the value of t 1 - α/2 from the table.

1 - α/2 = 1 - 0.01/2 = 1 - 0.005 = 0.995

The critical value is 3.012

The rejection region is area > 3.012

b) Ha: μ > 10

This is a right tailed test

n = 23

α = 0.1

We would reject the null hypothesis if the test statistic is greater than the table value of 1 - α

1 - α = 1 - 0.1 = 0.9

The critical value is 1.319

The rejection region is area > 1.319

c) Ha: μ > 10

This is a right tailed test

n = 99

α = 0.05

We would reject the null hypothesis if the test statistic is greater than the table value of 1 - α

1 - α = 1 - 0.05 = 0.95

The critical value is 1.66

The rejection region is area > 1.66

d) Ha: μ < 10

This is a left tailed test

n = 11

α = 0.1

We would reject the null hypothesis if the test statistic is lesser than the table value of 1 - α

1 - α = 1 - 0.1 = 0.9

The critical value is 1.363

The rejection region is area < 1.363

e) H0: μ = 10

Ha: μ ≠ 10

This is a two tailed test

n = 20

Since α = 0.05, we would find the critical value corresponding to 1 - α/2 and reject the null hypothesis if the absolute value of the test statistic is greater than the value of t 1 - α/2 from the table.

1 - α/2 = 1 - 0.05/2 = 1 - 0.025 = 0.975

The critical value is 2.086

The rejection region is area > 2.086

f) Ha: μ < 10

This is a left tailed test

n = 77

α = 0.01

We would reject the null hypothesis if the test statistic is lesser than the table value of 1 - α

1 - α = 1 - 0.01 = 0.99

The critical value is 2.376

The rejection region is area < 2.376

7 0

2 years ago