Plzzzzz help,.............

Natasha2012 [34]

137.2
30
$298.30
390
5970
3050
16
150
5500000

8 0

3 years ago

Five students wrote a mathematics test. The average mark was 68. If the marks for four of the students were 75, 62, 84 and 53, t

konstantin123 [22]

Answer:

66

Step-by-step explanation:

Use the formula for the mean of a set of numbers:

sum of the numbers

average = --------------------------------

count of numbers

Here we know that the average mark was 68, so we can write:

75 + 62 + 84 + 53 + x

average = 68 = ----------------------------------

5

or 274 + x

68 = -------------------

5

Solving for x, we multiply both sides by 5: 340 = 274 + x.

Subtracting 274 from both sides effectively isolates x:

340 = 274 + x

- 274 -274

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

66 = x

The fifth student's mark was 66.

4 0

3 years ago

Matt is saving to buy a new motorcycle. If he deposits $70 at the end of each month in an account that pays an annual interest r

gladu [14]

P = $70, p = 2.5% = 0.025
q = 1 + 0.025 / 12 = 1.002
Future value of a periodic deposit:
A = P · q · ( q^30 - 1 ) / ( q - 1 )
A = 70 · 1.002 · ( 1.002^30 - 1 ) / ( 1.002 - 1 )
A = $2,166
Answer:
He will have $2.166 in 30 months.

6 0

3 years ago

Read 2 more answers

The cycle time for trucks hauling concrete to a highway construction site is uniformly distributed over the interval 40 to 75 mi

jeka57 [31]

Answer:

0.8333 = 83.33% probability that the cycle time exceeds 50 minutes if it is known that the cycle time exceeds 45 minutes

Step-by-step explanation:

A distribution is called uniform if each outcome has the same probability of happening.

The uniform distributon has two bounds, a and b, and the probability of finding a value higher than x is given by:

$P(X > x) = \frac{b - x}{b - a}$

Uniformly distributed over the interval 40 to 75 minutes.

This means that $a = 40, b = 75$

It is known that the cycle time exceeds 45 minutes

This means that we can use $a = 45$

What is the probability that the cycle time exceeds 50 minutes?

$P(X > 50) = \frac{75 - 50}{75 - 45} = 0.8333$

0.8333 = 83.33% probability that the cycle time exceeds 50 minutes if it is known that the cycle time exceeds 45 minutes

8 0

3 years ago

Determine whether y varies directly with x. If so, find the constant of variation and write the equation.

kotykmax [81]

Answer: B. No

Step-by-step explanation:

Direct variation has the following form:

$y=kx$

Where the constant of variation is "k".

By definition, in direct variation, when the variable "x" changes, tha variable "y" changes in proportion to the variable "x".

As you can observe in the table, when the value of the variable "x" increase, the values of the variable "y" decrease, therefore we can conclude that it is not a direct variation.

Then the answer is the option B.

6 0

3 years ago