C
given 1 /( 3 + √2 )
then rationalise the denominator by multiplying the numerator/ denominator by the conjugate of the denominator
the conjugate of 3 + √2 is 3 - √2
1 / (3 + √2 ) × (3 - √2 ) / (3 - √2 )
= (3 - √2 ) /( 9 - 2 ) = (3 - √2 ) / 7
We are to show that if X ⊆ Y then (X ∪ Z) ⊆ (Y ∪ Z) for sets X, Y, Z.
Assume that a is a representative element of X, that is, a ∈ X. By the definition of union, a ∈ X ∪ Z. Now because X ⊆ Y and we assumed a ∈ X, then a ∈ Y by the definition of subset. And because a ∈ Y, then a ∈ Y ∪ Z by definition of union.
We chose our representative element, a, and showed that a ∈ X ∪ Y implies that a ∈ Y ∪ Z and this completes the proof.
Answer:
H0 ; μ ≤ 4 pCi/L
Ha ; μ > 4 pCi/L
The null hypothesis is that the concentration of dangerous, cancer-causing radon gas in her classroom is less than or equal to the safe level of 4pCi/L
H0 ; μ ≤ 4 pCi/L
The alternative hypothesis is that the concentration of dangerous, cancer-causing radon gas in her classroom is greater than the safe level of 4pCi/L.
Ha ; μ > 4 pCi/L
Step-by-step explanation:
The null hypothesis (H0) tries to show that no significant variation exists between variables or that a single variable is no different than its mean. While an alternative Hypothesis (Ha) attempt to prove that a new theory is true rather than the old one. That a variable is significantly different from the mean.
The null hypothesis is that the concentration of dangerous, cancer-causing radon gas in her classroom is less than or equal to the safe level of 4pCi/L
H0 ; μ ≤ 4 pCi/L
The alternative hypothesis is that the concentration of dangerous, cancer-causing radon gas in her classroom is greater than the safe level of 4pCi/L.
Ha ; μ > 4 pCi/L
Total customers are = 360
Number of polled people who purchased ice cream = 260
Number of polled people who purchased both ice cream and yogurt = 250
Hence, people who purchased only ice cream are=
And 
are people who purchased yogurt.
So, people who purchased yogurt only = 
Okay so first we need to find how many days are in March and February. March has 31 days and because this year was a leap year February has 29 days.
The next step is to convert days to hours.
March: 31x24=744
February: 29x24=696
Now its time to graph
