Answer:
The nearest time is 15 years or 180 months
Center: 0,0
vertex: 5,0
vertex2 (-5,0)
Answer:
Step-by-step explanation:
The axis of symmetry lies exactly halfway between the given x = 1 and x = -5.
The axis of symmetry is x = -2.
The 'halfway' value is also the 'average' of 1 and -5: -4/2, or -2.
The axis of symmetry is x = -2.
Given that,
Sample size= 83
Mean number= 39.04
Standard deviation= 11.51
We know the critical t-value for 95% confidence interval which is equal to 1.989.
We also know the formula for confidence interval,
CI=( mean number - critical t-value*standard deviation/(sample size)^(1/2), mean number + critical t-value*standard deviation/(sample size)^(1/2))
So, we have
CI= (39.04 - 1.989*11.51/83^(1/2), 39.04 + 1.989*11.51/83^(1/2)
CI= (39.04 - 2.513,39.04 + 2.513)
CI= (36.527,41.553)
Therefore, 95% confidence interval for these data is (36.527,41.553), and this result interpret that the true value for this survey sample lie in the interval (36.527,41.553).