Rearrange all and make the letter red the subject

According to records, the amount of precipitation in a certain city on a November day has a mean of 0.10 inches; with a standard

Alecsey [184]

Answer:

Probability that the mean daily precipitation will be 0.09 inches or less for a random sample of 40 November days is 0.103.

Step-by-step explanation:

We are given that according to records, the amount of precipitation in a certain city on a November day has a mean of 0.10 inches; with a standard deviation of 0.05 inches.

A random sample of 40 November days is taken(taken over many years).

Let $\bar X$ = sample mean daily precipitation

The z score probability distribution for sample mean is given by;

Z = $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\mu$ = population mean = 0.10 inches

$\sigma$ = population standard deviation = 0.05 inches

n = sample of days = 40

Now, the probability that the mean daily precipitation will be 0.09 inches or less is given by = P( $\bar X$ $\leq$ 0.09 inches)

P( $\bar X$ $\leq$ 0.09 inches) = P( $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ $\leq$ $\frac{0.09-0.10}{\frac{0.05}{\sqrt{40} } }$ ) = P(Z $\leq$ -1.265) = 1 - P(Z < 1.265)

= 1 - 0.8971 = 0.1029

The above probability is calculated by looking at the value of x = 1.265 from the z table which will lie between x = 1.26 and x = 1.27 which has an area of 0.89617 and 0.89796 respectively.

Hence, the probability that the mean daily precipitation will be 0.09 inches or less for a random sample of 40 November days is 0.103.

8 0

3 years ago

Gabe made a rectangular sandbox for his brother to play in. Gabe wants to paint only the sides of the sandbox. A prism has a len

alukav5142 [94]

Answer: The surface area of the sides of the sandbox that Gabe wants to paint is 47ft2

Step-by-step explanation:

Hi to answer this we have to apply the formula:

Surface Area of a rectangular prism = 2lw + 2wh + 2lh

Where:

l= length

w= width

h= height

Since the sandbox is open , it has one less surface (length x width), we have to add only one lw term.

Surface Area of the sandbox = lw + 2wh + 2lh

A = (4x5) + 2( 5x1.5) + 2( 4x1.5)

A = 20+15+12

A= 47 ft2

4 0

4 years ago

Joanna went school supply shopping. She spent $27.75 on notebooks and pencils. Notebooks cost $2.30 each and pencils cost $1.25

GaryK [48]

Answer:

The answer is A. 5 notebooks and 13 pencils

Step-by-step explanation:

1. Identify your x and y variables.

x - number of notebooks

y - number of pencils

2. Set up two equations to come up with a system of linear equations.

x + y = 18

2.3x + 1.25y = 27.75

3. In order to solve for one of the variables (either x or y), multiply the first equation with the additive inverse (when added together, the answer is zero; one number will be positive while the other number will be negative) of the coefficient of either x or y, so you can eliminate that variable. In this case, I choose the coefficient of y which is 1.25. So, the first equation will look like this:

-1.25(x + y) = 18

-1.25x - 1.25y = -22.50

4. Next, eliminate the y variable and solve for x.

-1.25x - 1.25y = -22.50

2.3 x + 1.25 y = 27.75

__________________

1.05 x = 5.25

1.05 1.05

x = 5 Joanna bought 5 notebooks.

5. Then, solve for y.

5 + y = 18

y = 18 - 5

y = 13 Joanna bought 13 pencils.

If you want to check your work, just plug in 5 and 13 into one of the two original equations. Simplify the equations, and you should get a true statement.

5 + 13 = 18

18 = 18

6 0

4 years ago

Someone help please

madreJ [45]

-4 and 3 are integers
-2.9 is a real number
5/8 is rational, due to the fact that it can be put into a fractional form.

4 0

3 years ago

If a population gets multiplied by 2 every 5 years, what does it get multiplied by each year?

DerKrebs [107]

Answer:

0.2.5

Step-by-step explanation:

2.5 x 5 = 2

7 0

3 years ago

Read 2 more answers