Answer:
The 85% confidence interval for the population proportion that claim to always buckle up is (0.7877, 0.8441).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
They randomly survey 391 drivers and find that 319 claim to always buckle up.
This means that 
85% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
The lower limit of this interval is:

The upper limit of this interval is:

The 85% confidence interval for the population proportion that claim to always buckle up is (0.7877, 0.8441).
Answer: 16 + z
Step-by-step explanation:
It's just 9 + 7 plus 2z - z, subtract the 2z by the z, you get 1z, which is better off being written as just z.
Answer:
310
Step-by-step explanation:
The maximum possible number is obtained when each family owns one appliance only. That total is ...
60 + 85 +70 +95 = 310
The maximum possible number of families is 310.
Answer:
$2.50
Step-by-step explanation:
Given the daily pay formula :
P(b)=5/2b+45
P(b) = employee’s total daily pay
b = number of bushels of peaches picked
Hence from the fórmula ; rate which employees are paid per bushel. Of peach picked is the gradient of the equation :
According to the intercept slope formula:
y = mx + c ; where m = slope or gradient
From the equation :
P(b)=5/2b+45
The slope or gradient is 5/2 ; hence, employees are paid $5/2 per bushel of peaches picked.
$5/2 = $2.50
<em>when we solve the equation it will become
x</em>² + 9x<em>= 0
now here a = 1 , b = 9 and c = 0
by using quaderatic formula
x = -b +,-</em>√<em>b </em>²<em>- 4ac / 2a ( 2a is divided by all terms )
by putting values
x = - 9 +,</em><em>- </em>√<em>81 / 2(1) ( </em>√<em>81 = 9)</em><em>
x = -9 + 9 / 2 and x = -9 -9 /2
x = 0 and x = -18 /2 = -9
now there are two values for x one is- 9 and other is 0
so we put -9 as the value of x then answer will be zero..</em>