Answer:
Step-by-step explanation:
Hello!
Your study variable is X: "number of ColorSmart-5000 that didn't need repairs after 5 years of use, in a sample of 390"
X~Bi (n;ρ)
ρ: population proportion of ColorSmart-5000 that didn't need repairs after 5 years of use. ρ = 0.95
n= 390
x= 303
sample proportion ^ρ: x/n = 303/390 = 0.776 ≅ 0.78
Applying the Central Limit Theorem you approximate the distribution of the sample proportion to normal to obtain the statistic to use.
You are asked to estimate the population proportion of televisions that didn't require repairs with a confidence interval, the formula is:
^ρ±
* √[(^ρ(1-^ρ))/n]
=
= 2.58
0.78±2.58* √[(0.78(1-0.78))/390]
0.0541
[0.726;0.834]
With a confidence level of 99% you'd expect that the interval [0.726;0.834] contains the true value of the proportion of ColorSmart-5000 that didn't need repairs after 5 years of use.
I hope it helps!
Answer: it will take 9 hours.
Step-by-step explanation:
The rain is falling at the rate of 1.5 inches per hour. This means that the height of water in the barrel is increasing in arithmetic progression.
The formula for determining the nth term of an arithmetic sequence is expressed as
Tn = a + d(n - 1)
Where
a represents the first term of the sequence.
d represents the common difference.
n represents the number of terms in the sequence.
From the information given,
a = 18 inches
d = 1.5 inches
The expression becomes
Tn = 18 + 1.5(n - 1)
For the number of hours it would take to collect 30 inches of rain in the barrel, Tn = 30
Therefore,
30 = 18 + 1.5(n - 1)
1.5(n - 1) = 30 - 18
1.5(n - 1) = 12
n - 1 = 12/1.5 = 8
n = 8 + 1
n = 9
Answer:
The correct number of basic operations that exist in mathematics is four (addition, subtraction, multiplication and division) because the definition of an operation is the carrying out of a task by the application of principles and these four operation are arithmetic operations that have precedence rules or order of operations, such that we must first multiply or divide before adding or subtracting
Division is different from simply multiplying by a fraction because in Euclidean division, the result is a quotient and a remainder, which shows that division can yield more than one result while multiplication yields a single result
For subtraction and addition, one of the differences is that subtraction cannot be simply commuted
a - b = -(b - a)
Subtraction is non-associative;
a - b - c when arranged as (a - b) - c and a - (b - c), can yield different results depending on operation order which is unlike addition
Therefore, the four basic operations in mathematics are addition, subtraction, multiplication and division
Step-by-step explanation:
Answer:
3x-1
Step-by-step explanation:
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