2x3(5-4)/6.2<br> Algebra

Of the total population of American households, including older Americans and perhaps some not so old, 17.3% receive retirement

Alex Ar [27]

Answer:

47.54% probability that more than 20 households but fewer than 35 households receive a retirement income

Step-by-step explanation:

We use the binomial aproxiation to the normal to solve this question.

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 samples 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:

$p = 0.173, n = 120$ . So

$\mu = E(X) = np = 120*0.173 = 20.76$

$\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{120*0.173*0.827} = 4.14$

In a random sample of 120 households, what is the probability that more than 20 households but fewer than 35 households receive a retirement income?

We are working with discrete values, so this is the pvalue of Z when X = 35-1 = 34 subtracted by the pvalue of Z when X = 20 + 1 = 21.

X = 34

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

$Z = \frac{34 - 20.76}{4.14}$

$Z = 3.2$

$Z = 3.2$ has a pvalue of 0.9993

X = 21

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

$Z = \frac{21 - 20.76}{4.14}$

$Z = 0.06$

$Z = 0.06$ has a pvalue of 0.5239

0.9993 - 0.5239 = 0.4754

47.54% probability that more than 20 households but fewer than 35 households receive a retirement income

6 0

3 years ago

How to do this question plz answer me step by

Jet001 [13]

Answer:

481.92

Step-by-step explanation:

First find the increase

466.98 * 3.2%

466.98 * .032

14.94336

Add this to the original amount

466.98+14.94336

481.92336

Round to 2 decimal places

481.92

7 0

3 years ago

An aquarium is being filled at a rate of 2.5 inches per second. The equationLaTeX: y=2.5xy = 2.5 x is used to determine the heig

Reika [66]

Answer:

Step-by-step explanation:

Given the equation y = 2,5x

y is the height of the water

x is the time.

To get the range of values of the height at t = 60s, we will substitute x = 60 into the function

y = 2.5(60)

y = 150 in

Hence the range of the situation is [0, 150].

The domain will be all positive integers i.e xEZ

3 0

3 years ago

Raffle tickets were sold for a school fundraiser to parents, teachers, and students. 563 tickets were sold to teachers. 888 more

Llana [10]

Given :

Raffle tickets were sold for a school fundraiser to parents, teachers, and students. 563 tickets were sold to teachers. 888 more tickets were sold to students than to teachers. 904 tickets were sold to parents.

To Find :

How many tickets were sold to students.

Solution :

Ticket sold to teachers, T = 563 .

Ticket sold to parents, P = 904 .

Let, ticket sold to students are S.

Now, it is given that :

S = T + 904

S = 563 + 904

S = 1467 students

Therefore, tickets sold to students are 1467 .

Hence, this is the required solution.

6 0

3 years ago

Please help I’m in a hurry and need the answer!!

UkoKoshka [18]

Answer:

56 cm Squared

Step-by-step explanation:

area of rectangle =10×5=50

area of smaller rectangle =3×2=6

area of the shape is 56

4 0

3 years ago

2x3(5-4)/6.2 Algebra