Answer:
Step-by-step explanation:
We want to determine a 95% confidence interval for the mean mean test score of students.
Number of sample, n = 25
Mean, u = 81.5
Standard deviation, s = 10.2
For a confidence level of 95%, the corresponding z value is 1.96. This is determined from the normal distribution table.
We will apply the formula
Confidence interval
= mean ± z score ×standard deviation/√n
It becomes
81.5 ± 1.96 × 10.2/√25
= 81.5 ± 1.96/× 2.04
= 81.5 ± 3.9984
The lower end of the confidence interval is 81.5 - 3.9984 =77.5
The upper end of the confidence interval is 81.5 + 3.9984 = 85.5
Therefore, with 95% confidence interval, the mean test score of students is between 77.5 and 85.5
I think she can use it 8 times
Answer:
The base of the triangle has a size of 20 cm, while each side has a size of 40 cm.
Step-by-step explanation:
An isosceles triangle is one that has two sides with an identical value, and one side with a different value from the previous ones. Thus, in the case the base will have a different value from the sides. In this regard, the perimeter (the sum of the sides) of the triangle is 100 cm, and the longest sides are twice the size of the base. Therefore, to determine the value of each side of the triangle, the following calculation must be performed:
X + 2X + 2X = 100
5X = 100
X = 100/5
X = 20
Thus, the base of the triangle has a size of 20 cm, while each side has a size of 40 cm.
Answer:
3,973 ( I really don't know for sure , just letting you know but I tried )
Step-by-step explanation:
9(-7) * 9(-7) + 4 = 3,973
Answer:
Step-by-step explanation:
Let's find each person's hourly rate. If Kyla can cut and split a cord of wood in 5.5 hours, Kyla can cut and split of a cord of wood in one hour. Similarly, Ronson can cut and spit of a cord of wood in one hour.
Therefore, working together, they can split of a cord of wood.
Thus, it will take them to cut and split a cord of wood.