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2 answers:
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Answer:
The correct option is B) 0.0228
Step-by-step explanation:
Consider the provided information.
The manager of a grocery store has taken a random sample of 100 customers. The average length of time it took the customers in the sample to check out was 3.1 minutes. The population standard deviation is known to be 0.5 minute.
Thus, the value of n = 100, and σ = 0.5
We want to test to determine whether or not the mean waiting time of all customers is significantly more than 3 minutes.
The null and alternative hypotheses are,
and
Compute the test statistic
By using the table.
P value = P(Z>2) = 0.0228
Hence, the correct option is B) 0.0228
Answer: 35
Step-by-step explanation:
Given : The IQs of 700 applicants to a certain college are approximately normally distributed with a mean of 115 and a standard deviation of 11.
i.e. and
Let x denotes the IQs of applicants to college.
If the college requires an IQ of at least 97, then, the probability that students have IQ less than 97:-
[By using z-table]
Number of students will be rejected on this basis of IQ = Total students x Probability of students have IQ less than 97
= 700 x 0.0505 = 35.35 ≈ 35
Hence, about 35 students will be rejected on this basis of IQ, regardless of their other qualifications .