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2 years ago

11

The time (in number of days) until maturity of a certain variety of tomato plant is Normally distributed with mean μ. You select

a simple random sample of four plants of this variety and measure the time until maturity. The four times, in days, are as follows: 63 69 62 66 with standard deviation 3.16.
Required:
Calculate the 99% confidence interval for population mean μ. Find the closest answer

1 answer:

VLD [36.1K]2 years ago

7 0

Answer: 60.93 < μ < 69.07

Step-by-step explanation: The true mean of a set of data is between an interval of values with a percentage of precision, e.g., a <u>99% confidence interval</u> means we are 99% confident the true mean is between the lower and upper limits.

To find the interval, use

x± $z\frac{s}{\sqrt{n}}$

z is z-score related to the % of confidence level

In this case, a 99% confidence interval is 2.576

x is sample mean

Calculating:

$x=\frac{63+69+62+66}{4}$

x = 65

65± $2.576\frac{3.16}{\sqrt{4}}$

65±4.07

Confidence Interval: 60.93 < μ < 69.07

Meaning that we are 99% sure the population means is between 60.93 and 69.07.

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Determine whether the value is a discrete random variable, continuous random variable, or not a random variable. a. The number

Fiesta28 [93]

Answer:

Discrete variables are those whose distribution will only take a finite number of values which are represented by integer values only.

Continous variables on the other hand could have an infinite number of points inbetween two integer values. With the values inbetween being decimals.

Step-by-step explanation:

a. The number of textbook authors now sitting at a computer :

A discrete random variable

Number of authors will be an integer value.

b. The height of a randomly selected giraffe ;

Continous random variable

Possible height value : h > 0

c. The responce to the survey question "Did you smoke in the last week"

It is not a random Variable

The response isn't numeric

d. The amount of rain in City B during April

It is a continous random variable

Possible values ; amount of rain > 0

e. The time it takes to fly from City A to City B

It is a continous random variable

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Possible values : t > 0

f. The number of light bulbs that burn out in the text week in a room with 17 bulbs

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6 0

3 years ago

HELP!! I WILL MARK YOU BRANLIEST IF YOU RESPOND THE FASTEST AND IF ITS CORRECT :)

Kruka [31]

Answer:

45

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

Warren has a container which holds 22 books of the same shape and size. The exact breakdown of his books is shown below:

ohaa [14]

Given:

Total number of book = 22

Number of white books = 6

Number of Purple books = 9

Number of green books = 7

To find:

The probability that Warren takes out a green book in both draws (with replacement).

Solution:

We know that,

$\text{Probability}=\dfrac{\text{Favorable outcomes}}{\text{Total outcomes}}$

$P(\text{White})=\dfrac{6}{22}$

$P(\text{Purple})=\dfrac{9}{22}$

$P(\text{green})=\dfrac{7}{22}$

After replacement, the probability of event remains the same and the independent.

The probability that Warren takes out a green book in both draws is:

$P=P(\text{green})\times P(\text{green})$

$P=\dfrac{7}{22}\times \dfrac{7}{22}$

$P=\dfrac{49}{484}$

Therefore, the correct option is (a).

7 0

3 years ago

Use the quadratic formula to solve the equation to the exact value or round to two decimal places.

lys-0071 [83]

First set everything to 0.
${x}^{2} + x - 5$
Giving you A= 1 , B= 1 and C= -5
Then input everything into the quadratic formula and either solve by hand or use a calculator.
Note exact values are found by hand, decimals are found using a calculator.

6 0

3 years ago

Suppose that the weights of 5400 registered female Labrador retrievers in the United States are distributed normally with a mean

Maurinko [17]

Answer:

$N= 4543$ Labrador retrievers

Step-by-step explanation:

We know that the mean $\mu$ is:

$\mu = 62.5$

and the standard deviation $\sigma$ is:

$\sigma=2.5$

The probability that a randomly selected Labrador retriever weighs less than 65 pounds is:

$P(X$

We calculate the Z-score for X =65

$Z = \frac{X-\mu}{\sigma}\\\\Z =\frac{65-62.5}{65}=1$

So

$P(X$

Looking in the table for the standard normal distribution we have to:

$P(Z$ .

Finally the amount N of Labrador retrievers that weigh less than 65 pounds is:

$N = P(X$

$N = 0.8413*5400$

$N= 4543$ Labrador retrievers

6 0

3 years ago