Answer:
So we use the t-distribution to compute a confidence interval for the average age of people using online dating services
Step-by-step explanation:
Confidence interval for a mean.
We have to decide between the t-distribution and the z-distribution.
T-distribution: We use the sample standard deviation.
Z-distribution: We use the population standard deviation.
In this problem:
The average age of those that were using online dating services was 35 years old with a sample standard deviation of 12 years.
So we use the t-distribution to compute a confidence interval for the average age of people using online dating services
Answer:
is B))))
Step-by-step explanation:
brainliest pls
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Answer:
D
Step-by-step explanation:
Answer:
the probability that two 18 year old boys chosen at random will have heights greater than 185cm is 0.403
Step-by-step explanation:
P( x > 193) = 0.15
= 1- p(x less than or equal 193)
= 1 -p( z < (x- u) /sigma)
= 1- p( z< (193 - 187)/ sigma)
= 1- p( z< 6/ sigma)
P(z< 6/sigma) = 1 - 0.15
P(z < 6/sigma)= 0.85
6/sigma =1.036
Sigma= 6/1.036
Sigma= 5.79
P( x> 185) = 1- p( x< 185)
= 1- p (z < (185- 187)/5.79)
= 1- p( z< -0.345)
= 1- 0.365
= 0.635
P (x> 185) = 0.635 × 0.635
=0.403
