Answer:
Step-by-step explanation:
Hello!
To study the threshold of hering the researcher took a random sample of 80 male college freshmen.
The students underwent an audiometry test where a tome was played and they had to press a button when they detected it. The researcher recorded the lowest stimulus level at which the tone was detected obtaining a sample mean of X[bar]= 22.2 dB and a standard deviation of S= 2.1 dB
To estimate the population mean, since we don't have information about the variable distribution but the sample size is greater than 30, you can use the approximation of the standard normal distribution:
X[bar] ± 
Where the semiamplitude or margin of error of the interval is:
d= 
Using a 95% level 
d= 1.965 * 
d= 0.46
The point estimate of the population mean of the threshold of hearing for male college freshmen is X[bar]= 22.2 db
And the estimation using a 95%CI is [21.74;22.66]
I hope this helps!
Answer: 2, 3, 5
Step-by-step explanation: 6*6 is 6^2 and 6*6*6 is 6^3 and you can add the exponents, so the last one is 6^5.
Answer:
cot . (x- π/2)= - tanx
Step-by-step explanation:
cot . (x- π/2)= - tanx
cot .x - cot π/2= - tanx
cot π/2= 1/tanπ/2
But tan π/2= ∞
cot π/2 = 1/∞= 0
cotx - 0= - tanx
cot x = - tanx
cosx/sinx= - sinx/cosx Putting values of cot and tan
cosx/ sinx ( sinx/cos x) = -sinx/cos x (sinx/cos x )
Multiplying both sides with sinx/cos x
1= - sin²x/cos²x
cos²x= - sin²x as cosx = -sinx
It is important so you can be more fluent or faster in knowing bigger problems