Answer:
$236.40
Step-by-step explanation:
Mrs. Blanda's truck holds 19.7 gallons of gas. She used 4 full tanks of gas last month.
1 full tank holds 19.7 gallons of gas
4 full tank hold 4*19.7 gallons of gas
4 full tank = 78.8 gallons of gas used last month
She paid $3 for each gallon
We need to find the amount she paid for 78.8 gallons
78.8 * 3= 236.4
Mrs. Blanda spend on gas last month = $236.40
Answer: a) Required minimum sample size= 219
b) Required minimum sample size= 271
Step-by-step explanation:
As per given , we have
Margin of error : E= 5% =0.05
Critical z-value for 90% confidence interval : 
a) Prior estimate of true proportion: p=28%=0.28
Formula to find the sample size :-

Required minimum sample size= 219
b) If no estimate of true proportion is given , then we assume p= 0.5
Formula to find the sample size :-

Required minimum sample size= 271
The diameter is a line that stretches across the middle of a circle from end to end. The radius is one half of this line, stretching from the center of the circle to a point on the side of the circle. This means that the diameter is 2 times the length of the radius. 2 times 2 is 4, meaning that the diameter is 4 inches.