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3 years ago

What is the probability of drawing a black card or a face card from a standard deck of 52 cards

Mathematics

1 answer:

mash [69]3 years ago

8 0

26 black cards plus 12 face cards = 38 out of 52. About a 73% chance.

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What is one half ( 1/2 ) squared?

lorasvet [3.4K]

Answer:

$(\frac{1}{2} )^{2} =\frac{1^2}{2^2} = \frac{1} {4}}$

When squaring a fraction, square both numerator AND denominator

7 0

3 years ago

Read 2 more answers

A house purchased for $230,000 has lost 6% of its value each year for the last four years. What is the house worth now?

lutik1710 [3]

You can use the compound growth to work this out,

Firstly you need to make a multiplier for -6%;
1-(6/100) = 0.94

The you times the amount of money by 0.94 to the power of 4 because you are working out 4 years:
230000*0.94^4 = 179527.26

The answer is $179527.26,
Hope this helps! :)

3 0

3 years ago

Factor completely

ZanzabumX [31]

Use the (-b + - sqrt( b^2 - 4ac) ) /2a Formula.
a = 1 b= 10 c= 24
so you get .. (x+6 )(x+4) A

4 0

4 years ago

Willie changes the quadratic function f(x)=x2?6x+14 to vertex form f(x)=a(x?h)2+k. If Willie does this correctly, what is the va

andrew11 [14]

Answer:

The value of k is 5.

Step-by-step explanation:

Since we know we can convert function's quadratic form to vertex form by completing the square.

f(x)=x2?6x+14

We will add and subtract 9 to our equation in order to complete the square.

$1(x^{2} ?6x+9)-9+14$

Upon completing the square and combining like terms we will get,

$1(x?3)^{2} +5$

Upon comparing Willie's vertex form with our expression we can see that k is 5.

Therefore, the value of k is 5.

8 0

4 years ago

A marketing researcher wants to find a 96% confidence interval for the mean amount those visitors spend per person per day while

ki77a [65]

Answer:

$n=(\frac{2.054(12)}{4})^2 =37.97 \approx 38$

So then the minimum sample to ensure the condition given is n= 38

Step-by-step explanation:

Notation

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

$\sigma=12$ represent the population standard deviation

n represent the sample size

ME = 4 the margin of error desired

Solution to the problem

When we create a confidence interval for the mean the margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (a)

And on this case we have that ME =4 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (b)

The critical value for 96% of confidence interval now can be founded using the normal distribution. The significance is $\alpha=1-0.96 =0.04$ . And in excel we can use this formula to find it:"=-NORM.INV(0.02;0;1)", and we got $z_{\alpha/2}=2.054$ , replacing into formula (b) we got:

$n=(\frac{2.054(12)}{4})^2 =37.97 \approx 38$

So then the minimum sample to ensure the condition given is n= 38

5 0

3 years ago