Simplify 6x+9/15x^2 divided by 16x-12/10^4

Maggie's brother is 11 years younger than three times her age. The sum of their ages is 41.

brilliants [131]

Answer:

Maggie is 13 years old.

Step-by-step explanation:

The explanation is attached.

3 0

2 years ago

Suppose the weights of Farmer Carl's potatoes are normally distributed with a mean of 8.0 ounces and a standard deviation of 1.1

svet-max [94.6K]

Answer:

a) 0.9959 = 99.59% probability that the mean weight is less than 9.3 ounces

b) 0.0129 = 1.29% probability that the mean weight is more than 9.0 ounces

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal 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.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Mean of 8.0 ounces and a standard deviation of 1.1 ounces.

This means that $\mu = 8, \sigma = 1.1$

(a) If 5 potatoes are randomly selected, find the probability that the mean weight is less than 9.3 ounces?

$n = 5$ means that $s = \frac{1.1}{\sqrt{5}} = 0.4919$

This probability is the pvalue of Z when X = 9.3. So

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

By the Central Limit Theorem

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

$Z = \frac{9.3 - 8}{0.4919}$

$Z = 2.64$

$Z = 2.64$ has a pvalue of 0.9959

0.9959 = 99.59% probability that the mean weight is less than 9.3 ounces

(b) If 6 potatoes are randomly selected, find the probability that the mean weight is more than 9.0 ounces?

$n = 6$ means that $s = \frac{1.1}{\sqrt{6}} = 0.4491$

This probability is 1 subtracted by the pvalue of Z when X = 9. So

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

$Z = \frac{9 - 8}{0.4491}$

$Z = 2.23$

$Z = 2.23$ has a pvalue of 0.9871

1 - 0.9871 = 0.0129

0.0129 = 1.29% probability that the mean weight is more than 9.0 ounces

8 0

3 years ago

Tanyss's house has 25 windows. Her brother has washed 22 of the windows. What percent of the windows has her brother washed?

AveGali [126]

Answer:

88

Step-by-step explanation:

7 0

2 years ago

Which will have a higher effective interest rate a payday loan for $2300 do in 15 days of the fee of $120 or a payday or loan fo

Elan Coil [88]

Answer:

A payday loan for $2300 due in 13 days with a fee of $120, because it has a shorter period

Step-by-step explanation:

8 0

2 years ago

What is your favorite color? A large survey of countries, including the United States, China, Russia, France, Turkey, Kenya, and

Ipatiy [6.2K]

Answer:

Step-by-step explanation:

We would set up the hypothesis test.

For the null hypothesis,

p = 0.24

For the alternative hypothesis,

p ≠ 0.24

This is a two tailed test

Considering the population proportion, probability of success, p = 0.24

q = probability of failure = 1 - p

q = 1 - 0.24 = 0.76

Considering the sample,

Sample proportion, P = r/n

Where

r = 12

n = 52

P = 12/52 = 0.23

We would determine the test statistic which is the z score

z = (P - p)/√pq/n

z = (0.23 - 0.24)/√(0.24 × 0.76)/52 = - 0.17

Recall, population proportion, P = 0.24

The difference between sample proportion and population proportion(p - P) is 0.24 - 0.23 = 0.01

Since the curve is symmetrical and it is a two tailed test, the p for the left tail is 0.24 - 0.01 = 0.23

the p for the right tail is 0.24 + 0.01 = 0.25

These proportions are lower and higher than the null proportion. Thus, they are evidence in favour of the alternative hypothesis. We will look at the area in both tails. Since it is showing in one tail only, we would double the area

From the normal distribution table, the area below the test z score in the left tail 0.43

We would double this area to include the area in the right tail of z = 0.17 Thus

p = 0.43 × 2 = 0.86

The level of significance is 5%

Since alpha, 0.05 < than the p value, 0.86, then we would fail to reject the null hypothesis. Therefore, at 5% significance level, this information does not imply that the color preference of all college students is different (either way) from that of the general population.

7 0

3 years ago