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2 years ago

Help please I need it

Mathematics

1 answer:

postnew [5]2 years ago

6 0

A. 40 pounds of seeds for 6-acre fields

The answer is

$\frac{6}{40}=0.15\text{ acres per pound}$

B. 11 pounds of flour at $7

The answer is

$\frac{11}{7}=\text{ 1.57 pounds per dollar}$

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Plz Help!!!

leonid [27]

Answer:

a and b

Step-by-step explanation:

6 0

3 years ago

Time spent using e-mail per session is normally distributed, with mu equals 11 minutes and sigma equals 3 minutes. Assume that

liq [111]

Answer:

a) 0.259

b) 0.297

c) 0.497

Step-by-step explanation:

To solve this problem, it is important to know the normal probability distribution and the central limit theorem.

Normal probability distribution

Problems of normally distributed samples are 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 random variable X, with mean $\mu$ and standard deviation $\sigma$ , a large sample size can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$

In this problem, we have that:

$\mu = 11, \sigma = 3$

a. If you select a random sample of 25 sessions, what is the probability that the sample mean is between 10.8 and 11.2 minutes?

Here we have that $n = 25, s = \frac{3}{\sqrt{25}} = 0.6$

This probability is the pvalue of Z when X = 11.2 subtracted by the pvalue of Z when X = 10.8.

X = 11.2

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

By the Central Limit Theorem

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

$Z = \frac{11.2 - 11}{0.6}$

$Z = 0.33$

$Z = 0.33$ has a pvalue of 0.6293.

X = 10.8

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

$Z = \frac{10.8 - 11}{0.6}$

$Z = -0.33$

$Z = -0.33$ has a pvalue of 0.3707.

0.6293 - 0.3707 = 0.2586

0.259 probability, rounded to three decimal places.

b. If you select a random sample of 25 sessions, what is the probability that the sample mean is between 10.5 and 11 minutes?

Subtraction of the pvalue of Z when X = 11 subtracted by the pvalue of Z when X = 10.5. So

X = 11

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

$Z = \frac{11 - 11}{0.6}$

$Z = 0$

$Z = 0$ has a pvalue of 0.5.

X = 10.5

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

$Z = \frac{10.5 - 11}{0.6}$

$Z = -0.83$

$Z = -0.83$ has a pvalue of 0.2033.

0.5 - 0.2033 = 0.2967

0.297, rounded to three decimal places.

c. If you select a random sample of 100 sessions, what is the probability that the sample mean is between 10.8 and 11.2 minutes?

Here we have that $n = 100, s = \frac{3}{\sqrt{100}} = 0.3$

This probability is the pvalue of Z when X = 11.2 subtracted by the pvalue of Z when X = 10.8.

X = 11.2

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

By the Central Limit Theorem

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

$Z = \frac{11.2 - 11}{0.3}$

$Z = 0.67$

$Z = 0.67$ has a pvalue of 0.7486.

X = 10.8

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

$Z = \frac{10.8 - 11}{0.3}$

$Z = -0.67$

$Z = -0.67$ has a pvalue of 0.2514.

0.7486 - 0.2514 = 0.4972

0.497, rounded to three decimal places.

5 0

3 years ago

Doubling the dimensions of a rectangle increases the area by a factor of 4.

aksik [14]

p → q represents the original conditional statement and the contrapositive of the original conditional statement. Then the correct options are A and E.

The missing options are given below.

<h3>What is dilation?</h3>

Dilation is the process of increasing the size of an item without affecting its form. Depending on the scale factor, the object's size can be raised or lowered.

There is no effect of dilation on the angle.

Doubling the dimensions of a rectangle increases the area by a factor of 4.

If p represents doubling the dimensions of a rectangle and q represents the area increasing by a factor of 4.

Then the true statement will be

Then the correct options are A and E.

More about the dilation link is given below.

brainly.com/question/2856466

#SPJ1

8 0

2 years ago

tavon has a $15 gift card that lose $3 for 30- day period It is not used. he has a $40 that loses $1.50 for each day period it i

Anna11 [10]

The number of 30- period until the value if the give card be equal is 20 30- day period

<h3>How to write and solve equation</h3>

let

Number of 30- day period = x

Card 1:

50 - 2x

Card 2:

40 - 1.50x

50 - 2x = 40 - 1.50x

50 - 40 = -1.50x + 2x

10 = 0.50x

divide both sides by 0.50

x = 10/0.50

x = 20

In conclusion, it will take 20 30- day period until the value of the given card can be equal.

Complete question:

Tavon has a $50 gift card that loses $2 for each 30-day period it is not used. He has a $40 card that loses $1.50 for each 30-day period it is not used.