Triangles with a 90 degree angle. We use the sine, cosine and tangent functions to determine the missing angles and sides.
Answer:
21
Step-by-step explanation:
Using<em> Simple Random Sampling</em>, we can estimate the sample size by the formula
where
n = sample size
Z = the z-score corresponding to the confidence level 99.5%
S = the assumed standard deviation = 3 seconds
e = margin of error = 2 seconds
<em>It is worth noticing that the higher the confidence level, the larger the sample should be.
</em>
The z-score corresponding to a confidence level of 99.5% can be obtained either with a table or the computer and equals
Z = 3.023
Replacing the values in our formula
So the size of the sample should be at least 21.
Answer:
1.benchmark fractions
2. equivalent fractions
Step-by-step explanation:
Hope it helps!
Answer:
Let x represents the week and y represents the seashells
As per the statement:
Dora has 10 seashells and plans to add 2 shells every week.
"2 shells every week" means 2x
⇒y = 10 + 2x
It is also given, Jerri has 4 seashells and plans to add 5 shells every week.
"5 shells every week" means 2x
⇒ y = 4 + 5x
The system of equation would be used:
y = 10 + 2x
y = 4 + 5x
Since, the girls have the same number of seashells
⇒
Subtract 4 from both sides we get;

Subtract 2x from both sides we get;

Divide by 3 both sides we have;
x = 2 weeks.
Therefore, the number of weeks would it be before the girls have the same number if seashells is, 2 weeks.