Answer:
8 weeks
Step-by-step explanation:
Given data
Matteo
Amount= $400
Spending per week= $10
Hence his balance after x weeks is given as
y=400-10x-------------1
Luca
Amount= $200
Spending per week= $15
Hence his balance after x weeks is given as
y=200+15x-------------2
Equate 1 and 2
400-10x=200+15x
collect like terms
400-200=15x+10x
200=25x
x= 200/25
x= 8 weeks
Hence it will take 8 weeks
Graph each side of the equation and the solution is what the x-value is at the point of intersection. In this case is about -1.25.
:)))
Answer:
The test is left - tailed
We cannot reject the organization's claim ( its cheapest screens will truly last less than 2.8 years)
Step-by-step explanation:
Sample size, n = 61
Sample mean, 
Standard deviation, 
Significance level, α=0.02
Null hypothesis, 
Alternative hypothesis, 
It is clearly seen from the alternative hypothesis, that it is a left tailed test. It is not tailed towards the two directions.
Calculate the test statistic:

Calculate the P-value:
P(Z < -3.35) = 0.0002
Since (p-value = 0.0002) < (α=0.02), the null hypothesis is rejected.
It can therefore be concluded that the mean of the cheapest screen is less than 2.8 years. i.e. the cheapest screen will last less than 2.8 years
The incorrect inequality is g > 80. The symbol ">" means greater than. So g > 80 would translate to meaning Kyle's grandmother is greater than 80. However, the problem states that his grandmother is not more than 80, meaning she is either 80 or younger. So the inequality should be g ≤ 80, or Kyle's grandmother is less than or equal to 80 years of age.
Solving for Y:
1) Subtract -2x from both sides: -3y=15-2x
2) Divide by -3 on both sides: y=-5+(2/3)x
Final Answer: y = (2/3)x-5