To solve this, we use the z test.
The formula:
z = (x – u) / s
where x is sample value = 20, u is the mean = 15, and s is
the standard deviation = 2.5
z = (20 – 15) / 2.5
z = 2
Since we are looking for values greater than 20, this is
right tailed test. We use the standard distribution tables to find for P.
P = 0.0228
Therefore:
number of students = 100 * 0.0228 = 2.28
<span>2 to 3 students will get greater than 20 measurement</span>
If you’re looking for the probability it’s 1/10
The answer is x = -2. The steps are in the image below.
Hope this helps!!!!!!!!
Please give me brainliest!!!!!!!!!!!
Answer:
It will take 4.84 years
Step-by-step explanation:
The initial amount that Matt invested was $1669. It means that principal is
P = 1669
It was compounded 12 times per year. So
n = 12
The rate at which the principal was compounded is 2%. So
r = 2/100 = 0.02
The formula for compound interest is
A = P(1+r/n)^nt
A = total amount in the account at the end of t years.
A = 1,844.38
Therefore
1,844.38 = 1669(1+0.02/12)^(12×t)
1,844.38/1669 = (1.0017)^(12t)
1.1051 = (1.0017)^(12t)
Taking log to base 10 of both sides, it becomes
Log 1.1051 = log 1.0017^(12t)
Log 1.1051 = 12tlog 1.0017
0.043 = 0.00074 × 12t
0.043 = 0.00888t
t = 0.043/0.00888
t = 4.84 years
