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3 years ago

10

Kena calculates that she spends 15% of a school day in science class. If she spends 75 minutes in science class, how many minute

s does Kena spend in school?

1 answer:

ankoles [38]3 years ago

5 0

Answer:

Step-by-step explanation:

You might be interested in

A random sample of 100 automobile owners in thestate of Virginia shows that an automobile is driven onaverage 23,500 kilometers

Anastaziya [24]

Answer:

a) 22497.7 < μ< 24502.3

b) With 99% confidence the possible error will not exceed 1002.3

Step-by-step explanation:

Given that:

Mean (μ) = 23500 kilometers per year

Standard deviation (σ) = 3900 kilometers

Confidence level (c) = 99% = 0.99

number of samples (n) = 100

a) α = 1 - c = 1 - 0.99 = 0.01

$\frac{\alpha }{2} =\frac{0.01}{2}=0.005\\ z_{\frac{\alpha }{2}}=z_{0.005}=2.57$

Using normal distribution table, $z_{0.005$ is the z value of 1 - 0.005 = 0.995 of the area to the right which is 2.57.

The margin of error (e) is given as:

$e= z_{0.005}\frac{\sigma}{\sqrt{n} } = 2.57*\frac{3900}{\sqrt{100} } =1002.3$

The 99% confidence interval = (μ - e, μ + e) = (23500 - 1002.3, 23500 + 1002.3) = (22497.7, 24502.3)

Confidence interval = 22497.7 < μ< 24502.3

b) With 99% confidence the possible error will not exceed 1002.3

5 0

4 years ago

Find the equation of plane that contains P(1,-1,2) and has the normal n=2i+3j+5k (please answer quickly )

mixas84 [53]

Answer:

2x + 3y + 5z = 9

Step-by-step explanation:

The normal defines all the planes perpendicular to that vector. To isolate to a single plane, just apply the known point.

ax + by + cz = d

2x + 3y + 5z = d

2(1) + 3(-1) + 5(2) = 9

8 0

3 years ago

PLS HELP WITH 4 and 5 ASAPPP FOR BRAINLIEST

topjm [15]

Answer:

4. SAME SLOPE, SAME Y INTERCEPT.

When this happens... The system of Equations has an Infinite Number of solutions.

A IS YOUR ANSWER

5.

A system of Equations has no solution when the graph of the system are PARALLEL LINES.

OPTION D IS YOUR ANSWER.

5 0

3 years ago

Which equation represents a circle that contains the point (-5, -3) and has a center at (-2, 1)?

Paha777 [63]

Answer:

the second one

Step-by-step explanation:

trust me i've done this before

5 0

3 years ago

The net of a triangular prism is shown below. What is the surface area of the prism? A. 128 cm^2 B. 152 cm^2 C. 176 cm^2 D. 304

shtirl [24]

Answer:

B. 152 cm²

Step-by-step explanation:

To find the surface area using a net, do this:

Take apart the figure. We see that there are three rectangles and two triangles. Find the area of each ( $A=l*w$ ) and then add the values together:

The first rectangle on the left is the same as the one on the right.

$5*8=40$

Two measures are 40 cm².

The middle rectangle is:

$6*8=48$

48 cm²

The formula for the area of a triangle is $A=\frac{1}{2}*b*h$ :

$A=\frac{1}{2}*6*4\\\\A=\frac{1*6*4}{2}\\\\A=\frac{24}{2}\\\\ A=12$

The area of the two triangles is 12 cm².

Now add the values:

$40+40+48+12+12=152$

The area of the figure is 152 cm².

:Done

4 0

4 years ago