Answer:
a. z = 2.00
Step-by-step explanation:
Hello!
The study variable is "Points per game of a high school team"
The hypothesis is that the average score per game is greater than before, so the parameter to test is the population mean (μ)
The hypothesis is:
H₀: μ ≤ 99
H₁: μ > 99
α: 0.01
There is no information about the variable distribution, I'll apply the Central Limit Theorem and approximate the sample mean (X[bar]) to normal since whether you use a Z or t-test, you need your variable to be at least approximately normal. Considering the sample size (n=36) I'd rather use a Z-test than a t-test.
The statistic value under the null hypothesis is:
Z= X[bar] - μ = 101 - 99 = 2
σ/√n 6/√36
I don't have σ, but since this is an approximation I can use the value of S instead.
I hope it helps!
<span><u>Answer</u>
25c^2-4/9
<u>Explanation</u>
In this question you are expected to expand (5c+2/3)(5c-2/3)
(5c+2/3)(5c-2/3)=(5c×5c)-(5c×2/3)+(5c×2/3)-(2/3×2/3)
=25c^2-10c/3+10c/3-4/9
25c^2-4/9
The expanded form of (5c+2/3)(5c-2/3) is 25c^2-4/9 and this is what the question requires of you to do.</span>
Answer: 16
Solution:
1) Use letters to identify the variables:
Number of trumpets: t
Number of clarinets: c
2) Translate each statement into algebraic (mathematical) language.
2.1) Sold a total of 27 used trumpets and clarinets
=> t + c = 27
2.2) Trumpets cost $149 and clarinets cost $99
Total cost of the trumpets: 149t
Total cost of clarinets: 99c
Total cost = 149t + 99c
2.3) Total sales were $3223
=> 149t + 99c = 3223.
3) State the system of equations:
Equation (1) t + c = 27
Equation (2) 149t + 99c = 3223
4) Solve the system of equations:
4.1) Multiply equation 1 by 149:
=> 149t + 149c = 4023
4.2) Subtract the equation (2) from the equation obtained in 4.1
=> 149c - 99c = 4023 - 3223
=> 50c = 800
=> c = 800 / 50 = 16
5) Verify the solution:
From equation (1) t = 27 - 16 = 11
Total cost = 149*11 + 99*16 = 3223
Now you have a verified answer: they sold 16 clarinets
Multiply both sides by three to get 2x=30
Then divide both sides by 2 to get x=15
Answer:
its 698...............................
