heather can do 2 problems in 10 minutes....60 minutes in an hr
2/10 = x / 60...2 problems to 10 min = x problems to 60 min
10x = 120
x = 120/10
x = 12....so she can do 12 problems in 1 hr
Joel can complete 3 problems in 15 minutes...
3/15 = x / 60
15x = 180
x = 180/15
x = 12....so he can do 12 problems in 1 hr
so 24 problems can be done in 1 hr
Heather started with 3 problems done and Joel started with 2 problems done....added = 5 problems already done
and it is asking between 30 and 50 hrs.....so there is no equal sign in ur problem
ur answer is : 30 < 24x + 5 < 50 <==
Answer:
The 99% confidence interval for the mean commute time of all commuters in Washington D.C. area is (22.35, 33.59).
Step-by-step explanation:
The (1 - <em>α</em>) % confidence interval for population mean (<em>μ</em>) is:
Here the population standard deviation (σ) is not provided. So the confidence interval would be computed using the <em>t</em>-distribution.
The (1 - <em>α</em>) % confidence interval for population mean (<em>μ</em>) using the <em>t</em>-distribution is:
Given:
*Use the <em>t</em>-table for the critical value.
Compute the 99% confidence interval as follows:
Thus, the 99% confidence interval for the mean commute time of all commuters in Washington D.C. area is (22.35, 33.59).
cosec(2t)=1/sin(2t) ==> 1/(2×cos(t)×sin(t))
cos(2t)= 1-2sin²t
or 2cos²t-1
or cos²t - sin²t
after we knew this informations we have to write it in the question
1/2×sint×cost-1/1/2×sint×cost=cos2t
-2×sint×cost+1/2sint×cost/1/2sint×cost=cos2t
the 2sint×cost will gone
-2×sint×cost+1=cos2t
lets take cos2t =1-2sin²t
-2×sint×cost+1=1-2sin²t
-2sint×cost=-2sin²t
cost=sint
that means the t is equal to 45 because sin45 and cos45 equal to √2/2
hopefully i didn't waste your time by reading and not understanding my English is not that good sorry
Answer:
87 !
Step-by-step explanation:
