It is known that in the absence of treatment, 55% of the patients with a certain illness will improve. The Central Limit Theorem tells us that the percentages of patients in groups of 400 that improve in the absence of treatment are approximately normally distributed.
(a) Find the mean and standard deviation of the normal distribution given by the Central Limit Theorem. Round the standard deviation to one decimal place.
mean
%
standard deviation
%

(b) In what percentage of such groups (of 400) would 215 or fewer improve? Round your answer to one decimal place.
%

option 2 is correct.

step-by-step explanation:

we are given two inequality equation

x+y> 5 and -3x+2y< -2

first we draw the graph of both function using t-table method

equation: x+y> 5

for x=0, y=5

for x=-5, y=0

table:

x   :   0     5

y   :   5     0

test point (0,0) , 0> 5

false

equation: -3x+2y< -2

for x=0, y=-1

for x=2, y=4

table:

x   :   0     2

y   : -1       4

test point (0,0) , 0< -2

true

now we draw the graph. see the attachment for graph.

common region would be solution set.

option 2 is correct.

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,

step-by-step explanation:   divide the numerator by the denominator to get the decimal

it would still be 193

if divide by 100 then 1.93

i am not sure