The weights of bags of red gravel may be modelled by normal distribution with
mean 25.8 kg and standard deviation of 0.5 kg.
(a) determine the probability that a randomly selected bag of red gravel will
have a weight:
(i) less than 25 kg;

The probability is 0.0548 if the weight of the bag of red gravel is 25kg.

Step-by-step explanation:

P(x<25)

=

=

=

=

Using z-table:

P(x<25)

=

=

=0.0548

Hence, the probability is 0.0548.

7

step-by-step explanation:

the answer would be 7

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

y = mx + c ( m is the slope and c the y-intercept )

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form