Mark went to the store and spent a total of $18.90. What is the cost of 5 items is if one item cost $2.95?

If x=4 and y=5. The value of 3x-5y

Harrizon [31]

Answer:

13, I believe :)

3 0

3 years ago

Read 2 more answers

Avoiding an accident while driving can depend on reaction time. Suppose that reaction time, measured from the time the driver fi

Nadya [2.5K]

Answer:

2.5% of drivers have a reaction time more than 2.14 seconds

16% of drivers have a reaction time less than 1.78 seconds

84% of drivers have a reaction time less than 2.02 seconds

Step-by-step explanation:

The Empirical Rule(68-95-99.7 rule) states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

The normal distribution is symmetric, which means that 50% of the measures are below the mean and 50% are above.

In this problem, we have that:

Mean = 1.9s

Standard deviation = 0.12

What percentage of drivers have a reaction time more than 2.14 seconds?

2.14 = 1.9 + 2*0.12

So 2.14 is two standard deviations above the mean.

Of the 50% of the measures above the mean, 95% are within 2 standard deviations of the mean, so, below 2.14. The other 5% is above.

0.05*0.5 = 0.025

2.5% of drivers have a reaction time more than 2.14 seconds

What percentage of drivers have a reaction time less than 1.78 seconds?

1.78 = 1.9 - 0.12

So 1.78 is one standard deviation below the mean.

Of the 50% of the measures that are below the mean, 68% are within one standard deviation of the mean, that is, greater than 1.78.

100 - 68 = 32

0.32*50 = 0.16

16% of drivers have a reaction time less than 1.78 seconds

What percentage of drivers have a reaction time less than 2.02 seconds?

2.02 = 1.9 + 0.12

So 2.02 is one standard deviation above the mean.

Of the measures that are below the mean, all are below 2.02.

Of those that are above, 68% are below 2.02.

0.5 + 0.68*0.5 = 0.84

84% of drivers have a reaction time less than 2.02 seconds

5 0

3 years ago

Rectangle with area of 12 square units is dilated by a scale factor of 3. What is the area?

Olegator [25]

Answer:

36 units²

Step-by-step explanation:

rectangle with area of 12 square units is dilated by a scale factor of 3. What is the area?

Scale factor = Dimension of the new shape ÷ Dimension of the original shape.

we use the inverse formula

12 * 3 =

36 units²

-----------------------

check

36 : 12 = 3

the answer is good

7 0

2 years ago

A food manufacturer stores corn oil in a right circular cylindrical container. This container has a height of 12 inches, and a b

Akimi4 [234]

This is not a quiestion but the area of this shape is 401.92inches. A=2πrh+2πr2

8 0

3 years ago

Three spherical balls with radius r are contained in a rectangular box. two of the balls are each touching 5 sides of the rectan

olganol [36]

Answer:

The volume of the space between the balls and the rectangular box is $4r^{3}(6 - \pi)$

Step-by-step explanation:

The attachment below shows the description of the rectangular bow and the three spherical balls.

From the description,

Two of the balls are each touching 5 sides of the rectangular box, say the 5 sides touched by one of the balls are sides 1,2,3,4, and 5; then the other ball will touch sides 2,3,4,5, and 6).
The middle ball also touches four sides of the rectangular box, These four sides touched by the middle ball will be sides 2,3,4, and 5.

This means the balls are tightly fitted into the rectangular box.

Each of the balls has a radius r

Hence, The volume of one of the balls is given by the volume of a sphere

$Volume of a sphere = \frac{4}{3} \pi r^{3} \\$