Exercise 10-30 Cost Variance Investigation (LO 10-4)The director of cost management for Odessa Company uses a statistical control chart to help management determine when to investigate variances. The critical value is 1 standard deviation. The company incurred the following direct-labor efficiency variances during the first six months of the current year. January $ 500 F February 1,600 U March 1,400 U April 1,800 U May 2,100 U June 2,400 U The standard direct-labor cost during each of these months was $38,000. The controller has estimated that the firm’s monthly direct-labor variances have a standard deviation of $1,900.Required:a. Determine the cutoff value for investigation if the controller’s rule of thumb is to investigate all variances equal to or greater than 6 percent of standard cost. b. Based on the cutoff value, which of the month(s) will have their direct-labor efficiency variance investigated?

a. The cutoff value for investigation if the controller’s rule of thumb is to investigate all variances equal to or greater than 6 percent of standard cost is $2,280.

b.The month that will have their direct-labor efficiency variance investigated will be the month of since june variance is 2,400 and hence is above $2,280.

Explanation:

According to the given data, the standard direct-labor cost during each of these months was $38,000, therefore, in order to calculate  the cutoff value for investigation, we would have make the following calculation:

Cutoff value for investigation =6% of Standard cost =$38,000 *6% =$2,280

The month that will have their direct-labor efficiency variance investigated will be the month of since june variance is 2,400 and hence is above $2,280.

start by isolating the variable on one side by adding 43w^2 to both sides.   the equation will read:

25w^2+5=0

*subtract 5 from both sides*

25w^2=-5

*divide both sides by 25*

w^2=-1/5

*take the square root of both sides*

w=√(-1/5)

the square root of -1 is i.   the square root of 5 remains √5

the answer is i/√5.

hope this