Answer:
628
Step-by-step explanation:
We have the standard deviation of the sample, so we use the t-distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 12 - 1 = 11
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 11 degrees of freedom(y-axis) and a confidence level of 
. So we have T = 2.2
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 665 - 37 = 628 hours.
The answer is 628
Answer: D
To solve the equation we proceed as follows:
log5(10x-1)=log5(9x+7)
canceling out log5 we get:
(10x-1)=(9x+7)
solving for x we get:
10x-9x=7+1
x=8
thus the value of x=8
Step-by-step explanation:
<em>it was on brainly already</em>
The apartment complex has 20 apartment per buildings 4 apartment are 3 bedroom apartment, 7 are 2 bedroom unit,and 9 apartment are 1 bedroom units.if the apartment complex builds 50 buildings how many 3 bedroom units would they have?
Answer:
28/65000 as a decimal is 0.00043076923076923
Step-by-step explanation:
Answer:
19.77% of average city temperatures are higher than that of Cairo
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean 
and standard deviation 
, the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:
What percentage of average city temperatures are higher than that of Cairo?
This is 1 subtracted by the pvalue of Z when X = 21.4.
has a pvalue of 0.8023
1 - 0.8023 = 0.1977
19.77% of average city temperatures are higher than that of Cairo
