How many solutions does this equation have?

8_murik_8 [283]

What is it referring too? is there a graph to it???

4 0

3 years ago

In the following problem, check that it is appropriate to use the normal approximation to the binomial. Then use the normal dist

frosja888 [35]

Answer:

a) 0.9920 = 99.20% probability that 15 or more will live beyond their 90th birthday

b) 0.2946 = 29.46% probability that 30 or more will live beyond their 90th birthday

c) 0.6273 = 62.73% probability that between 25 and 35 will live beyond their 90th birthday

d) 0.0034 = 0.34% probability that more than 40 will live beyond their 90th birthday

Step-by-step explanation:

We solve this question using the normal approximation to the binomial distribution.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

Normal probability distribution

Problems of normally distributed distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .

In this problem, we have that:

Sample of 723, 3.7% will live past their 90th birthday.

This means that $n = 723, p = 0.037$ .

So for the approximation, we will have:

$\mu = E(X) = np = 723*0.037 = 26.751$

$\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{723*0.037*0.963} = 5.08$

(a) 15 or more will live beyond their 90th birthday

This is, using continuity correction, $P(X \geq 15 - 0.5) = P(X \geq 14.5)$ , which is 1 subtracted by the pvalue of Z when X = 14.5. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{14.5 - 26.751}{5.08}$

$Z = -2.41$

$Z = -2.41$ has a pvalue of 0.0080

1 - 0.0080 = 0.9920

0.9920 = 99.20% probability that 15 or more will live beyond their 90th birthday

(b) 30 or more will live beyond their 90th birthday

This is, using continuity correction, $P(X \geq 30 - 0.5) = P(X \geq 29.5)$ , which is 1 subtracted by the pvalue of Z when X = 29.5. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{29.5 - 26.751}{5.08}$

$Z = 0.54$

$Z = 0.54$ has a pvalue of 0.7054

1 - 0.7054 = 0.2946

0.2946 = 29.46% probability that 30 or more will live beyond their 90th birthday

(c) between 25 and 35 will live beyond their 90th birthday

This is, using continuity correction, $P(25 - 0.5 \leq X \leq 35 + 0.5) = P(X 24.5 \leq X \leq 35.5)$ , which is the pvalue of Z when X = 35.5 subtracted by the pvalue of Z when X = 24.5. So

X = 35.5

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{35.5 - 26.751}{5.08}$

$Z = 1.72$

$Z = 1.72$ has a pvalue of 0.9573

X = 24.5

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{24.5 - 26.751}{5.08}$

$Z = -0.44$

$Z = -0.44$ has a pvalue of 0.3300

0.9573 - 0.3300 = 0.6273

0.6273 = 62.73% probability that between 25 and 35 will live beyond their 90th birthday.

(d) more than 40 will live beyond their 90th birthday

This is, using continuity correction, P(X > 40+0.5) = P(X > 40.5), which is 1 subtracted by the pvalue of Z when X = 40.5. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{40.5 - 26.751}{5.08}$

$Z = 2.71$

$Z = 2.71$ has a pvalue of 0.9966

1 - 0.9966 = 0.0034

0.0034 = 0.34% probability that more than 40 will live beyond their 90th birthday

6 0

3 years ago

Trigonometry

Mazyrski [523]

Answer:

0.3491rad

Step-by-step explanation:

We are asked to convert 20° to radians.

#We know that 1° is equal to π/180 or 0.01745rad.

To convert any angle degrees to radians, we multiply it by π/180:

$=20\times\pi/180\\\\=0.3491 \ or \ \frac{\pi}{9}rad$

Hence, 20° converted to radians is 0.3491rad

3 0

3 years ago

What is the smallest positive integer, other than $1$, that is both a perfect cube and a perfect fourth power?

cupoosta [38]

<span>There are two approaches to translate this inquiry, to be specific:
You need to know a number which can go about as the ideal square root and also the ideal block root.
You need to know a number which is an ideal square and in addition an ideal 3D shape of a whole number.
In the primary case, the arrangement is straightforward. Any non-negative whole number is an ideal square root and in addition a flawless solid shape foundation of a bigger number.
A non-negative whole number, say 0, is the ideal square foundation of 0 and additionally an immaculate shape base of 0. This remains constant for all non-negative numbers starting from 0 i.e. 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
In the second case as well, the arrangement is straightforward however it involves a more legitimate approach than the primary choice.
A flawless square is a number which contains prime variables having powers which are a different of 2. So also, a flawless block is a number which includes prime variables having powers which are a numerous of 3. Any number which includes prime components having powers which are a various of 6 will be the answer for your inquiry; a case of which would be 64 which is the ideal square of 8 and an ideal 3D shape of 4. For this situation, the number 64 can be spoken to as prime variables (i.e. 2^6) having powers (i.e. 6) which are a different of 6.</span>

6 0

3 years ago

Read 2 more answers

4(2 - x) > -2x - 3(4x + 1)<br>solve for x

a_sh-v [17]

Answer: X> -11/10

Explanation:

7 0

3 years ago