Answer: 0.0775
Step-by-step explanation:
Given : Mean :
Standard deviation :
Sample size :
Since its normal distribution , then the formula to calculate the z-score is given by :-
For x= 28.2 hours
For x= 30 hours
The P- value =
Hence, the probabiliy that the average time spent stydying for the sampe was between 28.2 and 30 hours = 0.0775
Answer:
78.81%
Step-by-step explanation:
We are given;
Population mean; μ = 149
Sample mean; x¯ = 147.8
Sample size; n = 88
standard deviation; σ = 14
Z-score is;
z = (x¯ - μ)/(σ/√n)
Plugging in the relevant values;
z = (147.8 - 149)/(14/√88)
z = -0.804
From z-distribution table attached, we have; p = 0.21186
P(X > 147.8) = 1 - 0.21186 = 0.78814
In percentage gives; p = 78.81%
9514 1404 393
Answer:
see attached
Step-by-step explanation:
Find the y-values corresponding to x-values of 0 and 1, then plot those points and draw a line through them.
For x=0, ...
y = -4·0 -1 = -1 . . . . the point is (0, -1) . . . the y-intercept
For x=1, ...
y = -4·1 -1 = -5 . . . . the point is (1, -5)
The attached graph shows these points and the line through them.
