Missing question: How many executives should be surveyed?
Solution:
Mean = 13 hours
SD = 3 hours
Confidence level = 95%
Mean viewing time within a quarter of an hour = 0.25 = 1.96*3/sqrt (N)
Where N = Sample population
N = {(1.96*3)/0.25}^2 = 553.19 ≈ 554
Therefore, 554 executives should be surveyed to yield such results.
1st problem:
A = 630 cm
2nd problem:
A = 104 cm
All I can see on the picture you provided.
Answer:
<h2> In 8 hours he will set 1200 bricks</h2>
Step-by-step explanation:
In this problem, we are expected to estimate the number of bricks he can set in 8 hours.
let us convert hours to minutes we have
60 min make 1 hour
x min make 8 hours
cross multiply
x= 60*8
x= 480 min
We are assuming the same rate with which he sets 2.5 brick is the same as the rate with which he will set bricks for the 8 hours windows
so if the bricklayer sets
2.5 bricks in 1min
y bricks in 480 min
Cross multiply we have
y=2.5*480
y= 1200 bricks
hence in 8 hours, he will set 1200 bricks
B because it u and 9 friends each want the same amount from splitting 1.30 which gives you .13
Correct Ans:Option A. 0.0100
Solution:We are to find the probability that the class average for 10 selected classes is greater than 90. This involves the utilization of standard normal distribution.
First step will be to convert the given score into z score for given mean, standard deviation and sample size and then use that z score to find the said probability. So converting the value to z score:

So, 90 converted to z score for given data is 2.326. Now using the z-table we are to find the probability of z score to be greater than 2.326. The probability comes out to be 0.01.
Therefore, there is a 0.01 probability of the class average to be greater than 90 for the 10 classes.