If Anna pays $18 for a pack of 25 markers how much is each marker

The national average sat score (for verbal and math) is 1028. if we assume a normal distribution with standard deviation 92, wha

elena55 [62]

Let X be the national sat score. X follows normal distribution with mean μ =1028, standard deviation σ = 92

The 90th percentile score is nothing but the x value for which area below x is 90%.

To find 90th percentile we will find find z score such that probability below z is 0.9

P(Z <z) = 0.9

Using excel function to find z score corresponding to probability 0.9 is

z = NORM.S.INV(0.9) = 1.28

z =1.28

Now convert z score into x value using the formula

x = z *σ + μ

x = 1.28 * 92 + 1028

x = 1145.76

The 90th percentile score value is 1145.76

The probability that randomly selected score exceeds 1200 is

P(X > 1200)

Z score corresponding to x=1200 is

z = $\frac{x - mean}{standard deviation}$

z = $\frac{1200-1028}{92}$

z = 1.8695 ~ 1.87

P(Z > 1.87 ) = 1 - P(Z < 1.87)

Using z-score table to find probability z < 1.87

P(Z < 1.87) = 0.9693

P(Z > 1.87) = 1 - 0.9693

P(Z > 1.87) = 0.0307

The probability that a randomly selected score exceeds 1200 is 0.0307

5 0

3 years ago

Evaluate 2^−1 + 2^−1.

Diano4ka-milaya [45]

Answer:

1

Step-by-step explanation:

2^−1 + 2^−1

2x2^-1

1

4 0

3 years ago

Which of the following arithmetic sequences have a common difference of ? -4,-1.5,1,3.5,6,8.5 1.5,3,4.5,6,7.5

zavuch27 [327]

F(x+1) = f(x) + 2.5 with f(x) is the current number.

7 0

3 years ago

HELP PLZ!!! I'M GIVING 15 POINTS FOR IT!!!!!!

Sati [7]

Answer:

a. True

b. False

c. True

d. False

Step-by-step explanation:

a. True

Where, there are three straight lines intersecting one another, and whereby the sum of the interior angles formed between one of the straight lines and the other two is less than 180°, then the other two straight lines will cross if extended further on the same side of the figure where the sum of the intersecting angles between the lines was found to be less than 180°.

The converse statements is that

If three lines are drawn with two of the lines converging, then the third line can be drawn such that the sum of the interior angles between it and the other two lines is less than 180°

The contrapositive statements is that

If the sum of the interior angles between a first line and the other two lines is equal to 180° then the other two lines will not meet

b. False.

The answer is false is false because,

The length of the sides of the square must be equal

The interior angles of the square must also be equal

c. True

From Postulate 1, the sum of two adjacent angles on one side of the two intersecting lines is equal to 180°. So also on the other side of the intersection, the sum of the adjacent angles is equal to 180.

Therefore, we have

180° + 180° = 360°

The converse statements is that

If two lines meet at a point then the sum of angles at the point is 360°

The contrapositive statements is that

If the two lines do not meet, then the sum of angles on each line is 180°

d. False

A parallel line can be drawn from any point not on the line.

8 0

3 years ago

The Powerball lottery is played twice each week in 28 states, the Virgin Islands, and the District of Columbia. To play Powerbal

Alecsey [184]

Answer:

There are 3478761 ways to select the first 5 numbers

Step-by-step explanation:

As understood from the statement of this problem we assume that it does not matter the order in which the first 5 white balls are selected.

In this case it is a combination.

So, what we want to know is how many ways you can choose 5 white balls out of 55.

Then we use the formula of combinations:

$C(n, x) = \frac{n!}{x! (n-x)!}$

Where you have n elements and choose x from them.

Then we look for:

$C(55, 5) = \frac{55!}{5!(55-5)!}\\\\C(55, 5) = \frac{55!}{5!(50)!}\\\\C(55, 5) = 3478761$

6 0

3 years ago