PLEASE HELP ASAP!!! 7th GRADE MATH

Ardie bought 547 acres of land for development. If 29 acres of his purchase is reserved for a park, how many two-acre building l

9966 [12]

Hey there!

First, is he used 29 out of the 547 for a park, he can't use them for two acre building lots, so we must subtract:

547-29 = 518

If we want to know how many 2 acre building lots we can sell, we can divide 518 by 2, as dividing it by 2 sees how many times 2 goes into 518- essentially how many two acre lots are in 518 acres.

This gives us 259 two-acre building lots.

Hope this helps!

8 0

3 years ago

4. Amazon executives believe that at least 70% of customers would return a product 2 days after it arrives at their home. A samp

inysia [295]

Using the normal distribution and the central limit theorem, it is found that there is a 0.1635 = 16.35% probability of a sample result with 68% or fewer returns prior to the third day.

In a normal distribution with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

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

It 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, which is the percentile of X.
By the Central Limit Theorem, for a proportion p in a sample of size n, the sampling distribution of sample proportions has mean $\mu = p$ and standard error $s = \sqrt{\frac{p(1 - p)}{n}}$

In this problem:

Sample of 500 customers, hence $n = 500$ .

Amazon believes that the proportion is of 70%, hence $p = 0.7$

The mean and the standard error are given by:

$\mu = p = 0.7$

$s = \sqrt{\frac{p(1 - p)}{n}} = \sqrt{\frac{0.7(0.3)}{500}} = 0.0205$

The probability is the p-value of Z when X = 0.68, hence:

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

By the Central Limit Theorem

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

$Z = \frac{0.68 - 0.7}{0.0205}$

$Z = -0.98$

$Z = -0.98$ has a p-value of 0.1635.

0.1635 = 16.35% probability of a sample result with 68% or fewer returns prior to the third day.

A similar problem is given at brainly.com/question/25735688

7 0

2 years ago

Heart failure is due to either natural occurrences (89%) or outside factors (11%). Outside factors are related to induced substa

Firdavs [7]

Answer:

a) 11% probability that the first patient with heart failure that enters the emergency room has the conditions due to outside factors.

b) 0.0871 = 8.71% probability that third patient with heart failure that enters the emergency room is the first one due to outside factors.

c) The mean number of heart failure patients with the condition due to natural causes that enter the emergency room before the first patient with heart failure from outside factors is 9.09.

Step-by-step explanation:

We have these following probabilities:

89% probability that a patient has heart failure due to natural occurrences.

11% probability that a patient has heart failure due to outside factors.

A) What is the probability that the first patient with heart failure that enters the emergency room has the conditions due to outside factors?

We assume that causes of heart failure between individuals are independent, which means that the probabilities are the same for each patient. So:

11% probability that the first patient with heart failure that enters the emergency room has the conditions due to outside factors.

B) What is the probability that third patient with heart failure that enters the emergency room is the first one due to outside factors?

First two due to natural occurrences, each with 89% = 0.89 probability.

Third due to outside factors, with 11% = 0.11 probability. So

0.89*0.89*0.11 = 0.0871

0.0871 = 8.71% probability that third patient with heart failure that enters the emergency room is the first one due to outside factors.

C) What is the mean number of heart failure patients with the condition due to natural causes that enter the emergency room before the first patient with heart failure from outside factors?

11% with outside factors, so the mean number of patients before the first with outside factors is given by

m = 1/0.11 = 9.09

The mean number of heart failure patients with the condition due to natural causes that enter the emergency room before the first patient with heart failure from outside factors is 9.09.

4 0

3 years ago

Pls halp due today >_< thank you!

d1i1m1o1n [39]

Answer:

It is the first option: - $\sqrt{25}$ , - $\frac{22}{4}$ , -560%, -2 $\pi$