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3 years ago

Suppose a normal distribution has a mean of 16 and a standard deviation of 4.

Mathematics

2 answers:

olga55 [171]3 years ago

8 0

Answer:

Correct Answer is 2.5

Step-by-step explanation:

Lina20 [59]3 years ago

4 0

To calculate the number of standard deviations away from the mean, we first subtract the actual score from the mean, then divide the difference by the standard deviation. In this case, our actual score is 26, so we subtract from the mean of 16, then divide by the SD of 4
(26 - 16) / 4 = 2.5

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PLEASE HELP!!

Natasha2012 [34]

Answer:

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

Oil is pumped continuously from a well at a rate proportional to the amount of oil left in the well. Initially there were millio

JulijaS [17]

Answer:

The amount of oil was decreasing at 69300 barrels, yearly

Step-by-step explanation:

Given

$Initial =1\ million$

$6\ years\ later = 500,000$

Required

At what rate did oil decrease when 600000 barrels remain

To do this, we make use of the following notations

t = Time

A = Amount left in the well

So:

$\frac{dA}{dt} = kA$

Where k represents the constant of proportionality

$\frac{dA}{dt} = kA$

Multiply both sides by dt/A

$\frac{dA}{dt} * \frac{dt}{A} = kA * \frac{dt}{A}$

$\frac{dA}{A} = k\ dt$

Integrate both sides

$\int\ {\frac{dA}{A} = \int\ {k\ dt}$

$ln\ A = kt + lnC$

Make A, the subject

$A = Ce^{kt}$

$t = 0\ when\ A =1\ million$ i.e. At initial

So, we have:

$A = Ce^{kt}$

$1000000 = Ce^{k*0}$

$1000000 = Ce^{0}$

$1000000 = C*1$

$1000000 = C$

$C =1000000$

Substitute $C =1000000$ in $A = Ce^{kt}$

$A = 1000000e^{kt}$

To solve for k;

$6\ years\ later = 500,000$

i.e.

$t = 6\ A = 500000$

So:

$500000= 1000000e^{k*6}$

Divide both sides by 1000000

$0.5= e^{k*6}$

Take natural logarithm (ln) of both sides

$ln(0.5) = ln(e^{k*6})$

$ln(0.5) = k*6$

Solve for k

$k = \frac{ln(0.5)}{6}$

$k = \frac{-0.693}{6}$

$k = -0.1155$

Recall that:

$\frac{dA}{dt} = kA$

Where

$\frac{dA}{dt}$ = Rate

So, when

$A = 600000$

The rate is:

$\frac{dA}{dt} = -0.1155 * 600000$

$\frac{dA}{dt} = -69300$

<em>Hence, the amount of oil was decreasing at 69300 barrels, yearly</em>

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2 years ago

Ice cream sandwiches are wrapped in white paper before they are put in

Ket [755]

What’s the size of them?

4 0

2 years ago

Katy buys 4 DVDs every 2 weeks. How many DVDs will she buy in 14 weeks?

Lena [83]

Answer:

Step-by-step explanation:

Every 2 weeks 4 DVDs are purchased, so you have to multiply 14 times two, or 7 by 4. And the answer you get either way is 28.

4 0

2 years ago

30 POINTS!!!!! PLEASE HELP

Hoochie [10]

Answer:

a) For a constant increment in x-variable, there is a constant increment in y-variable, for example, for x = 0 to x = 0.5 (increment = 0.5) y-variable goes from 60 to 62 (increment = 2); the same is valid for any couple of (x,y) values. This behaviour is characteristic of linear equations.

b) slope:

m = (increment in y-variable)/(increment in x-variable) = 2/0.5 = 4

y-intercept:

y1 = m*x1 + h

60 = 4*0 + h

60 = h

equation: y = 4x + 60

where y represents scores and x represents hours spent studying

c) The slope indicates that you need to study 1 hour to increase your score in 4 points

The y-intercept indicates that you will get at least a score of 60, even though you hadn't studied

3 0

2 years ago