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2 years ago

Using proportional reasoning, about how many of 180 seventh grade students in school would like to snorkel

Mathematics

1 answer:

amm18122 years ago

3 0

Answer:

We need some aditional data. For example, the average number of students who like to snorkel in certain population.

Step-by-step explanation:

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For a certain river, suppose the drought length Y is the number of consecutive time intervals in which the water supply remains

AnnZ [28]

Answer:

a) There is a 9% probability that a drought lasts exactly 3 intervals.

There is an 85.5% probability that a drought lasts at most 3 intervals.

b)There is a 14.5% probability that the length of a drought exceeds its mean value by at least one standard deviation

Step-by-step explanation:

The geometric distribution is the number of failures expected before you get a success in a series of Bernoulli trials.

It has the following probability density formula:

$f(x) = (1-p)^{x}p$

In which p is the probability of a success.

The mean of the geometric distribution is given by the following formula:

$\mu = \frac{1-p}{p}$

The standard deviation of the geometric distribution is given by the following formula:

$\sigma = \sqrt{\frac{1-p}{p^{2}}$

In this problem, we have that:

$p = 0.383$

$\mu = \frac{1-p}{p} = \frac{1-0.383}{0.383} = 1.61$

$\sigma = \sqrt{\frac{1-p}{p^{2}}} = \sqrt{\frac{1-0.383}{(0.383)^{2}}} = 2.05$

(a) What is the probability that a drought lasts exactly 3 intervals?

This is $f(3)$

$f(x) = (1-p)^{x}p$

$f(3) = (1-0.383)^{3}*(0.383)$

$f(3) = 0.09$

There is a 9% probability that a drought lasts exactly 3 intervals.

At most 3 intervals?

This is $P = f(0) + f(1) + f(2) + f(3)$

$f(x) = (1-p)^{x}p$

$f(0) = (1-0.383)^{0}*(0.383) = 0.383$

$f(1) = (1-0.383)^{1}*(0.383) = 0.236$

$f(2) = (1-0.383)^{2}*(0.383) = 0.146$

Previously in this exercise, we found that $f(3) = 0.09$

$P = f(0) + f(1) + f(2) + f(3) = 0.383 + 0.236 + 0.146 + 0.09 = 0.855$

There is an 85.5% probability that a drought lasts at most 3 intervals.

(b) What is the probability that the length of a drought exceeds its mean value by at least one standard deviation?

This is $P(X \geq \mu+\sigma) = P(X \geq 1.61 + 2.05) = P(X \geq 3.66) = P(X \geq 4)$ .

We are working with discrete data, so 3.66 is rounded up to 4.

Either a drought lasts at least four months, or it lasts at most thee. In a), we found that the probability that it lasts at most 3 months is 0.855. The sum of these probabilities is decimal 1. So:

$P(X \leq 3) + P(X \geq 4) = 1$

$0.855 + P(X \geq 4) = 1$

$P(X \geq 4) = 0.145$

There is a 14.5% probability that the length of a drought exceeds its mean value by at least one standard deviation

8 0

3 years ago

The number on two consecutively numbered gym lockers have a sum of 127. What are the locker numbers?

kaheart [24]

63 and 64 is the answer

4 0

2 years ago

Jason bought 3 dozen eggs from the grocery store to bake some cakes how many eggs did Jason buy?

Snowcat [4.5K]

Answer:

He bought 36 eggs

Step-by-step explanation:

3x12=36

6 0

2 years ago

Read 2 more answers

Function g is a transformation of the parent quadratic function f. Which statements are true about this function?

sergey [27]

Answer: Function g reflected function f across the x-axis.

For function g, as x approaches negative infinity, g(x) approaches negative infinity.

Function f is symmetrical about the point (4,6).

4 0

2 years ago

Reuben learned in art class that a mosaic is made by arranging small pieces of colored material such as glass or tile to create

anastassius [24]

Pattern is the rule that guides the formation of a set.

The sequence of the first five mosaics is 5, 8, 11, 14, 17
The sequence is arithmetic
There are 32 tiles in the tenth mosaic.

From the given design, the number of tiles used is:

$T_1 = 5$

$T_2 = 8$

$T_3 = 11$

(a) The first five

Notice that the difference in the number of tiles of successive mosaic is 3.

This means that:

$T_4 = T_3 + 3 = 11 +3 = 14$

$T_5 = T_4 + 3 = 14 +3 = 17$

So, the sequence of the first five mosaics is 5, 8, 11, 14, 17

(b) The type of sequence

The sequence is arithmetic

This is so, because the difference in the number of tiles of successive mosaic is 3.

This difference is called the common difference

(c) The number of tiles in the tenth mosaic

The nth term of an arithmetic sequence is:

$T_n = T_1 + (n - 1) \times d$

In this case:

$T_1 = 5$

$d =3$

$n = 10$

So, we have:

$T_{10} = 5 + (10 - 1) \times 3$

$T_{10} = 5 + 9 \times 3$

$T_{10} = 5 + 27$

$T_{10} = 32$

There are 32 tiles in the tenth mosaic.

Read more about arithmetic sequence at:

brainly.com/question/18109692

5 0

2 years ago