Answer:
The approximate 90% confidence interval is;
70,244 to 70,732
Step-by-step explanation:
Here, we want to calculate the approximate 90% C.I for the situation
Mathematically;
CI = mean ± (z * SD)/√n
From the question;
mean = 70,438
SD = 645.3
n = 30
we can get z from the CI table
90% CI is same as; 1.645 z-score
So , substituting these values;
CI = 70,438 ± ( 1.645 * 645.3)/√30
CI = 70,438 ± 194
So the CI = 70,438 -194 to 70,438 + 194
= 70,244 to 70,732
Answer: C. 6x+18
Step-by-step explanation:
Use the distributive property
First multiply 6 times x which is 6x
Then multiply 6 times 3 which is 18
Keep the sign the same
Therefore, this should give you 6x+18
Elga's age is 50, and Alvin's age is 56. So, the sum of their ages is 106.
Answer:
y = 6
x = 0.2
Step-by-step explanation:
5x + y =7
20x + 2 = y
5x(4) + y(4) = 7(4)
20x + 4y = 28
(20x = 28 - 4y) = (20x = y - 2)
28 - 4y = y - 2
30 - 4y = y
30 = 5y
y = 6
5x + y =7
20x + 2 = y
y = 7 - 5x
7 - 5x = 20x + 2
5 - 5x = 20x
5 = 25x
x = 0.2
Answer:
Step-by-step explanation:
Given that the mean incubation time for a type of fertilized egg kept at a certain temperature is 25 days.
Let X be the incubation time for a type of fertilized egg kept at a certain temperature is 25 days.
X is N(25, 1)
a) Normal curve is in the attached file
b) the probability that a randomly selected fertilized egg hatches in less than 23 days
=
we convert x into Z score and use std normal distn table to find probability

i.e. we can say only 2.5% proportion will hatch in less than 23 days.