-9≤7-8w Find the solution Help please

Orlov [11]

3.45g+0.06kg+0.67g+690mg+2dg

8 0

3 years ago

A study of long-distance phone calls made from General Electric Corporate Headquarters in Fairfield, Connecticut, revealed the l

lesya692 [45]

Answer:

The probability that a call last between 4.2 and 4.9 minutes is 0.4599

Step-by-step explanation:

Let X be the length in minutes of a random phone call. X is a normal distribution with mean λ=4.2 and standard deviation σ=0.4. We want to know P(4.2 < X < 4.9). In order to make computations, we will use W, the standarization of X, given by the following formula

$W = \frac{X-\mu}{\sigma} = \frac{X-4.2}{0.4}$

We will use $\phi$ , the cummulative distribution function of W. The values of $\phi$ are well known and the can be found in the attached file

$P(4.2 < X < 4.9) = P(\frac{4.2-4.2}{0.4} < \frac{X-4.2}{0.4} < \frac{4.9-4.2}{0.4}) = P(0 < W < 1.75) = \\ \phi(1.75) - \phi(0) = 0.9599-0.5 = 0.4599$

We conclude that the probability that a call last between 4.2 and 4.9 minutes is 0.4599

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7 0

3 years ago

One number is 7 more than 3 times another number. Their sum is 63. Find

Alisiya [41]

Answer: 3x+7=a

a+X=63 a=63-x

Substitute into first formula

3x+7=63-x

4x=56

X=

26/2

X=13

A=50

Plug-in answers to check my work

50=3*13+7 46 not equal to 50

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Phone sux

Step-by-step explanation:

7 0

3 years ago

The population of a local species of flies can be found using an infinite geometric series where a1 = 940 and the common ratio i

alex41 [277]

A. Sigma notation

The formula for finding the nth value of the geometric series is given as:

an = a1 * r^n

Where,

an = nth value of the series

a1 = 1st value in the geometric series = 940

r = common ratio = 1/5

n = nth order

The sigma notation for the sum of this infinite geometric series is therefore,

(see attached photo)

B. Sum of the infinite geometric series

The formula for calculating the sum of an infinite geometric series is given as:

S = a1 / (1 – r)

Substituting the given values:

S = 940 / (1 – 1/5)

S = 1,175

6 0

4 years ago

Write an expression that is equivalent to (23.6-7.1a-4.2b)-(5.8b-9a)

KengaRu [80]

Let's simplify step-by-step.23.6−7.1a−4.2b−(5.8b−9a)Distribute the Negative Sign:=23.6−7.1a−4.2b+−1(5.8b−9a)=23.6+−7.1a+−4.2b+−1(5.8b)+−1(−9a)=23.6+−7.1a+−4.2b+−5.8b+9aCombine Like Terms:=23.6+−7.1a+−4.2b+−5.8b+9a=(−7.1a+9a)+(−4.2b+−5.8b)+(23.6)=1.9a+−10b+23.6

8 0

3 years ago

-9≤7-8wFind the solutionHelp please