Answer:
d. ( 63.9, 66.7)
Therefore at 90% confidence interval (a,b) = ( 63.9, 66.7)
Step-by-step explanation:
Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.
The confidence interval of a statistical data can be written as.
x+/-zr/√n
Given that;
Mean x = 65.3
Standard deviation r = 5.2
Number of samples n = 36
Confidence interval = 90%
z(at 90% confidence) = 1.645
Substituting the values we have;
65.3+/-1.645(5.2/√36)
65.3+/-1.645(0.866667)
65.3+/-1.42567
65.3+/-1.4
= ( 63.9, 66.7)
Therefore at 90% confidence interval (a,b) = ( 63.9, 66.7)
Answer:
Step-by-step explanation:
Answer:
Right answer is 10 I hope it's helps you
I think the answer is 48 hope this helps
Answer:
0.6832 = 68.32% probability that a given student will complete the test in more than 35 minutes but less than 43 minutes
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Mean of 41.0 minutes and a variance of 3.4 minutes.
This means that 
What is the probability, rounded to four decimal places, that a given student will complete the test in more than 35 minutes but less than 43 minutes?
This is the p-value of Z when X = 43 subtracted by the p-value of Z when X = 35.
X = 43



has a p-value of 0.7224
X = 35



has a p-value of 0.0392
0.7224 - 0.0392 = 0.6832
0.6832 = 68.32% probability that a given student will complete the test in more than 35 minutes but less than 43 minutes