Answer:
The 90% confidence interval for the mean score of all takers of this test is between 59.92 and 64.08. The lower end is 59.92, and the upper end is 64.08.
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
So it is z with a pvalue of 
, so 
Now, find the margin of error M as such
In which 
is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 62 - 2.08 = 59.92
The upper end of the interval is the sample mean added to M. So it is 62 + 2.08 = 64.08.
The 90% confidence interval for the mean score of all takers of this test is between 59.92 and 64.08. The lower end is 59.92, and the upper end is 64.08.
Answer:
Step-by-step explanation:
In probability, "AND" means "multiplication" and
"OR" means "addition".
We want the probability that she picks FAVORITE SHIRT "AND" FAVORITE PANT.
Probability that she picks favorite shirt = 3/5
Probability that she picks favorite pants = 2/4 = 1/2
Since, "AND", we "multiply" both to get:
3/5 * 1/2 = 3/10
Answer: 2 2/3 cups of flour
Step-by-step explanation: If one batch represents 1/4 of the total number of cookies he needs, then it can be deduced that he needs four total batches. If it requires 2/3 cups of flour for each batch and he needs 4 batches, you would multiply 2/3 by 4 to get the answer.
2/3 × 4 = 2 2/3
Answer:
10 days
Step-by-step explanation:
10 workers work 2 hrs a day for 5 days, so the work content is 10*5*2=100 manhours.
2 people work 5 hrs a day, so they deliver 10 manhours a day. To finish a work of 100 manhours,they’ll need 100/10=10 days.
The answer is 10 days.
