Answer:
The 98% confidence interval for the mean number of hours of study time per week for all students is (20.9, 25.1).
Step-by-step explanation:
Confidence interval:
Sample mean plus/minus the margin of error.
In this question:
Mean of 23.
Margin of error 2.1.
Then
23 - 2.1 = 20.9
23 + 2.1 = 25.1
The 98% confidence interval for the mean number of hours of study time per week for all students is (20.9, 25.1).
Yes, this identity is true. Those two operations are equivalent.
Answer:
47.5%
Step-by-step explanation:
Find the z-scores:
z = (x − μ) / σ
z₁ = (300 − 400) / 50 = -2
z₂ = (400 − 400) / 50 = 0
300 is 2 standard deviations below the mean, and 400 is 0 standard deviations from the mean.
From the empirical rule, 95% of a normal distribution is between -2 and +2 standard deviations. Since normal distributions are symmetrical, that means half of that is between -2 and 0 standard deviations.
95% / 2 = 47.5%
Answer:
b= 55 degrees
c= 125 degrees
Step-by-step explanation:
So angle B and 55 degree angle are vertical angles to they are congruent and opposite
Angle C and angle b =180 so subtract 55 from 180 to get missing angle C as 125 degrees
Answer:
128
Step-by-step explanation:
The two angles form a straight line so they add to 180
2m+62 + 3m +143 = 180
Combine like terms
5m+205=180
Subtract 205 from each side
5m+205-205=180-205
5m = -25
Divide by 5
5m/5 = -25/5
m = -5
We want to find the angle so we substitute the value of m into the the formula for the angle.
< RBM =3m +143 = 3(-5) +143 = -15+143 =128
